Hot Packs For Food Transport? Top Answer Update

These homemade heat packs are easy to make with just a few materials, inexpensive, and make a great gift too!

While these reusable heat packs are easy to make and use, there are a few questions that need to be answered –

What should I use the rice heat pack for?

The homemade heat packs can be used for sore muscles, discomfort or to warm up on a cold night.

You can add essential oils like lavender or peppermint to the rice before filling the heat pack, which not only smell great but are also soothing (lavender) and help with colds and respiratory problems (peppermint).

Who should use the heat packs?

Making your own rice heat packs makes them very easy to use for all ages. The problem with an electric heating pad is that they are not recommended for everyone.

The heat packs are great for athletes, people who exercise, gardeners – absolutely anyone can use the reusable heat packs.

How should you use the homemade heat packs?

These DIY Heat Packs are made for the microwave. Heat for 1-2 minutes, shake gently and apply to desired area.

You can also put the pack in the freezer and use it as a cold compress.

What should I fill the homemade heat packs with?

Long grain rice is the preferred filler, make sure it is NOT instant rice.

However, you can also use other grains such as beans, corn, wheat, barley or millet.

Dried cherry pits have also been used as a filler.

What should I use to make the homemade heat pack?

Cotton fabric is best. It can be found at any fabric or craft store and some discount stores like Walmart.

You can also make the heat packs out of white muslin and then make a sleeve for the heat pack to slide into – making the heat pack easier to clean.

What size should the heat packs be?

Any size will work. The ones I made are 5 inches x 8 inches after they’re filled.

The rectangular size is great for wrapping around your neck or knees.

Homemade Heat Packs Supplies

Fabric – cotton works best – the fabric I used was fat quarters that I bought at Walmart. Any fabric or craft store should have it, or any fabric from the yard will work well too. I found it super easy to cut the fat quarters as they were already the length I wanted. I got 3 heat packs from 1 Fat Quarter.

Long grain rice – make sure it’s not instant rice. You can also use other grains for the filling, such as beans, corn, wheat, barley, millet. Cherry stones are another alternative for filling.

Essential oils – this is optional, but I like them. Using lavender essential oil gives a calming feeling and using peppermint is good for a cold.

sewing machine

cutting mat (optional)

rotary cutter (optional)

scissors

ruler

pencils

thread

needle

funnel (not shown)

How to do a heat pack

cut fabric. Any size will work. Determine your finished size, then double the LENGTH and add 1/2 – 1 inch for seam allowance. These are cut – 6 inches by 18 inches – creating the finished 5 x 8 heat pack after sewing and stuffing. A cutting mat and rotary cutter work great, but you can also use a ruler and scissors. Fold the fabric in half, right sides together. Sew around all sides with a sewing machine. Be sure to leave about 2 inches of opening for stuffing. Turn the heat pack right side out and iron the seams. Use a funnel to fill rice. Fill about 3/4 full. For this heat pack size, I used 1 (3) pound bag of long grain rice for 3 heat packs. Plug the opening. Sew the opening shut with a needle and thread. I found it easiest to sew multiple heat packs at once and repeat the steps for each heat pack at once. So – cut the whole fabric, then sew, turn, iron, fill, sew up.

Giving away the Homemade Heat Packs is a great idea! You can put lotions, games, movies, snacks and more in a gift basket along with the heat packs. If you have a few reusable heat packs ready, you can easily pack them with some chicken soup, crackers, and other items for a friend or family member when they’re not feeling well.

If you make these homemade heat packs or any of my other recipes or projects – I’d love to hear your thoughts, leave a comment below in the comments section or tag me on Instagram #simpleeasycreative so I can see them!

Whether it’s a weekend morning and you’re baking pancakes or preparing multiple dishes for a holiday dinner, finding a way to keep food warm is often a necessity. Luckily, in your own kitchen, there are several ways to keep French toast, fried food, and even mashed potatoes from going cold.

One important thing to keep in mind is that food stored outside and not kept sufficiently warm or cool (below 40 F or above 150 F) can be unsafe to eat. Have a thermometer handy to check food temperature.

your oven

Some ovens actually have a “warm” setting, typically 170 to 200 F, or a warming drawer designed to keep food at an even, warm temperature. If your oven doesn’t have either, set it to 200 to 250 F. Transfer the cooked food to a baking sheet, ovenproof pot, or casserole dish and cover with aluminum foil before placing in the oven.

If you’re trying to keep pancakes, waffles, pancakes, or any other fried food warm, place them in a single layer on a cooling rack placed over a baking sheet to prevent them from becoming soggy or soggy. If necessary, cover loosely with foil to prevent the outside from browning any further.

For food that needs to be kept warm longer than 15 or 20 minutes, check that it’s at least 140 F with an instant-read thermometer; If not, increase the oven temperature a bit. Keep in mind that if you try to keep food warm for more than an hour or two, the texture of the food can become spongy or the flavor profile can change. Instead, consider reheating closer to serving time.

Slow cookers or chafing dishes

For hot vegetables, sauces, stews and soups, a slow cooker or chafing dish can be used on a low setting to keep food warm. Similar to an oven, if you plan to store food for more than an hour, you may notice a change in texture or flavor. Even though the appliance is set to Warm, the food may cook slightly slowly.

Rice cookers and other steam cookers

If you use a rice cooker to cook rice, the rice will most likely stay hot and moist for an hour or more while on the “warm” setting. When you steam cook, you can usually keep food warm by removing the heating element from the steamer (remove it from the hob or turn off the electric steamer) and set the pan aside. You may want to open the lid for a brief moment to let the steam escape so the food doesn’t continue cooking. Replace the lid and set aside until ready to serve.

cool bag or insulated bag

We might think of our cooler or insulated bag when transporting food that needs to be kept cold, but both are also great for keeping food warm. If food is not in a covered bowl, place in a covered container or wrap in aluminum foil and store in cooler or bag. Check the temperature of the food from time to time to make sure it doesn’t drop below 140F.

Warm plates to serve

When there isn’t much time between cooking the food and serving it, but enough time for the food to cool slightly, heating the plates on which the food is served is a solution. Make sure your plates are oven safe – ceramic plates retain heat well.

To reheat plates for serving, stack them in an oven at the lowest oven temperature, about 150 to 200 F, for 15 minutes. You can also use a warming drawer or toaster if they are large enough. Alternatively, you can heat the plates in the microwave for a minute or two. If you entertain a lot, you might want to invest in an electric plate warmer.

When reheating plates in the oven, make sure you always use an oven mitt, let others know the plate is hot, and don’t shake the plate by placing it in a cold place like a refrigerator. The plate can break due to the temperature shock from hot to cold.

aluminum foil

If you need to keep food warm for a short time, wrapping or covering with aluminum foil is sufficient. Just remember that the foil only stays in the heat for about 30 minutes.

If you’re trying to keep a roast, steak, or whole bird warm, tenting with aluminum foil while it rests will benefit the meat in two ways: It keeps it at a warm temperature while allowing the juices to redistribute . Just make sure you cover it loosely with foil; If you cover it tightly, you’ll make the hot meat sweat and lose that precious moisture you want to retain. A roast is at its best when it rests 10 to 20 minutes before carving, but the rest time depends on its size. A turkey can sit anywhere from 20 to 45 minutes depending on the size of the bird (the larger the bird, the longer the rest time). Steaks or chops should stand wrapped in foil for 5 minutes before serving.

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Here are the best thermoses for hot (and cold) food for the whole family.

To help you find one that suits your needs, we’ve researched top products that are great for wrapping up leftovers, meal prep, and dishes to include in kids’ lunch boxes. We tested how long our best models keep hot food warm and cold drinks chilled.

After extensive testing, the Thermos Stainless King Food Jar was the clear winner. This thermos kept food hot for a spectacular nine hours and cold for an amazing 14 hours. A cheaper option is Mira’s stainless steel vacuum insulated thermos, which comes in multiple colors and is easy to clean.

If you’re always on the go, you’ll quickly get used to a quick meal, but relying on fast food can also have rewards — both calorie-wise and financially. With the right storage containers, taking homemade food to the office, to school, or when traveling is a breeze.

“Always have an extra thermos or two [in the car] of whatever you’ve brought with you into the great outdoors. You’ll be glad to have them and more likely to consume what you need along the way, knowing there’s more waiting for you down the road. ” — Kate Bast, nature and forest therapy guide and founder of Shinrin-Yoku Madison

Available in multiple sizes, start small with the 8 or 12 ounce container and expand in size over time when an expanded collection is needed for a family. Just keep in mind that the 20 and 28 ounce versions have higher price points. However, this should keep your food warm for at least four hours. Some reviewers have even reported excellent heat retention for up to 12 hours.

The leak-proof Hydro Flask Insulated Food Jar is just as stylish as the company’s beverage-only models. Crafted with outdoor adventures in mind, the durable exterior is a favorite of nature and camping enthusiasts, and the 18/8 stainless steel interior ensures there is no taste transfer or lingering odors.

“Should it snow after consuming hot thermoses, fill it with clean snow. The residual heat will help melt it and ensure you have more water ready.” — Kate Bast, natural and forest therapy guide and founder of Shinrin-Yoku Madison

The exterior color choices include muted hues like pearl blue, Hawaiian blue, and light pink, giving this line a similar aesthetic to more expensive brands currently on the market. It has an average heat retention of about five hours and cold retention of up to 10 hours.

For a leak-proof and sweat-proof vessel at an affordable price, check out MIRA’s stainless steel thermos for lunch. It is easy to clean by hand due to the larger opening at the top and the rubber ring inside the lid can be removed for more adequate cleaning and to prevent mold growth.

“Think about the nutrition you need to match your exertion level and what’s most digestible,” says Bast. Their popular hot beverages include slices of apple or pear soaked in cider with maple syrup, white pine tea, and spruce needle tea. For hot dishes, Bast recommends bone broth, vegetable broth, or other soups that you can add protein to. For something heartier, she suggests a casserole or stew.

Cleaning in a home kitchen was a bit difficult for our tester. It can be put in the dishwasher, although the hot water and detergent could damage the exterior. Washing the inside of the lid requires a sponge and some hand details.

It is absolutely necessary to follow the instructions for use exactly, e.g. B. Warming the interior with hot water for five to ten minutes before adding food that will be eaten later. Our home tester found this kept hot food warm for 5 hours, even when opened every hour to test the temperature. It also kept cold drinks cool for 7 hours, with ice cubes still visible at the end of the test.

Children will love the Funtainer’s variety of colors and character themes. More importantly, a wide brim makes eating less challenging for little ones as they learn to use utensils, and the cool exterior won’t hurt their hands. Best of all, it’s light and compact enough for little hands to open and carry in their backpacks.

On hot days, Kate Bast, nature and forest therapy guide and founder of Shinrin-Yoku Madison, recommends hikers carry at least twice as much water as they think they need, even if it means carrying two or more thermoses. She also suggests putting hydration packs in water or filling a thermos with fruits that are high in water content, like watermelons, which can be frozen the night before to maximize coolness. On cool days, Bast carries a thermos with room temperature water and another with a hot or warm drink.

When it came time to clean up, our tester noted that while it’s dishwasher safe, you might be better off hand washing it. Food was caught in the lid, gasket and container, requiring scrubbing with a sponge.

Our home tester liked the double-walled insulation and compact size that adults can use for hot side dishes and drinks. However, our tester focused on one of the most important aspects of a thermos: how long does it keep your food warm? Thermos claims this keeps food warm for up to 5 hours, and it fell short in our testing. Mac and cheese only stayed hot for 2 hours, was still warm enough to eat after 4 hours, and had to be microwaved (in a separate container) after 5 hours. In terms of cold water, it lives up to its 9-hour claim, and ice cubes are still available after a full day’s work.

Ergonomically designed with kids in mind, the BPA-free Foogo is a parent favorite as its cool-to-the-touch 10-ounce body is the perfect size for a kid’s lunch. The base and lid are made of rubber so that the can is easier to grip even for smaller hands. Other advantages include cost efficiency and a robust, scratch-resistant housing.

“After our test, we were confident that the jar would work well for soups and other foods that are even hotter to begin with.” — Suzie Dundas , product tester

Our home tester purposely dropped the thermos and found that it wasn’t damaged in any way. In addition, its wide mouth is useful for eating straight from the container and when you need to wash it quickly by hand. Every component of this model can be safely washed in the top rack of your dishwasher, allowing for easy maintenance for busy professionals on the go.

Thermos claims liquids can stay hot for nine hours and cold for up to 14 hours, so we put that claim to the test in a home kitchen. Our reviewer filled all 16 ounces with freshly made mac and cheese, opening the thermos every hour to see if the temperature stayed consistent. Only in the ninth hour did the temperature drop. Additionally, it was excellent at keeping water ice cold, with our tester still observing ice cubes after 14 hours in the thermos.

Thanks to an extremely tight seal, the Thermos King is touted as providing maximum temperature retention for both hot and cold food. This is thanks to the insulation made of two stainless steel walls. Another key benefit is that the lid is designed to be used as a bowl along with the included standard size stainless steel folding spoon.

Final Verdict For a decently sized thermos that will keep foods like soup, stew and pasta hot for up to an impressive nine hours, look no further than the stainless steel Thermos King Food Jar. Kids, on the other hand, will love the fun colors and cool feel of the Thermos Foogo Wide Mouth Vacuum Insulated Stainless Steel Food Container.

What to look out for when buying a thermos for hot food

By Marshall Hell

draft

Thermoses for food are usually shorter and wider than thermoses for drinks. This allows you to pour contents like soup into the bottle – and eat out of it, too. Most have a screw-on lid that prevents spills. Some thermoses have extra seals or inner lids for added leak protection.

The Spruce Eats / Suzie Dundas

material

Stainless steel is the preferred material for thermos flasks. It does not absorb color or odors from hot food left in it for a long time and is easy to clean. An inner bottle is surrounded by a partial vacuum that does not conduct heat away from the bottle and keeps the contents warm. An outer casing, also usually steel, allows you to hold the container without condensing or burning your hand. The outer housing can also be treated with a coating or surrounded by plastic.

Even inexpensive models are usually made of vacuum-sealed stainless steel. However, the vacuuming process can also be used with other materials such as glass and plastic. Because they are not as durable as stainless steel, they are not recommended.

size

The size of a thermos flask largely depends on what you intend to use it for. Most adult thermoses tend to weigh around 16 ounces, and children’s are slightly smaller. Food will cool faster if there is too much air in the thermos. So if you want your food to stay hot for several hours, you want the best thermos for the amount of food you’re putting in it. If you just want the option of a small bowl of soup for lunch, you can go with 10 ounces or less. If you want to carry a hearty meal in your bottle, 16oz is probably a better choice.

Price

Thermoses tend to be fairly affordable, and you can usually expect to find a durable one for between $15 and $30. The more expensive models might have funnier colors, an extra strong seal in the lid, or specific accessories, but they all use the same stainless steel vacuum-sealed design.

The Spruce Eats / Suzie Dundas

brands/manufacturers

Thermos

Thermos is synonymous with the product it makes – Thermos. But unlike Kleenex and Tupperware, Thermos could not maintain the trademark of the term “thermos”. Founded in Germany, Thermos was the first company to figure out how to apply industrial vacuuming techniques for home use. Today, Thermos manufactures a wide range of insulated containers, from bottles and mugs to coolers and lunch boxes.

hydro flask

Engineered for the outdoors, Hydro Flask’s powder-coated bottles and jars are built to withstand heavy use. They are available in a variety of colors and come with a lifetime guarantee.

maintenance

A stainless steel thermos is relatively easy to clean. Because it doesn’t pick up smell or color from your food, you can treat it like any other dirty dishes and wash it with soap and water. Many thermoses are dishwasher safe, but not all. This is not due to the material, but to the construction: dishwashers can damage the vacuum seal. Inner lids and other accessories, such as folding forks, may also require an additional hand wash to remove accumulated dirt.

The Spruce Eats / Suzie Dundas

frequently asked Questions

How do I choose a thermos flask?

Before you buy a thermos, narrow down on a preferred size and what it will be used for most. This can range from drinks like coffee and tea to meals that need to get through a long day and transportation to after-school clubs and sports practice. Perhaps durability is the primary concern on long outdoor hikes. Check customer reviews to read common praise and complaints about each manufacturer’s product.

How does a thermos work?

Using a vacuum-sealed stainless steel design, an inner bottle keeps contents at a constant temperature as warm or cold air cannot easily enter or escape the bottle. The outer material, mostly made of hard plastic or steel, makes it easy to hold and transport the thermos flask without liquid escaping.

How long do thermos flasks keep the contents hot or cold?

High-quality thermos flasks keep food and drinks warm for a full 24 hours. More economical brands will typically maintain the original temperature of the contents for four to six hours.

Why trust the spruce?

Rachel Werner teaches culinary writing at Hugo House and has been selecting food-based companies for editorial coverage for over six years. Her product and restaurant reviews, food styling and photography have appeared in a variety of regional and national publications including Fabulous Wisconsin, BRAVA and Hobby Farms Magazine. For this round-up, she interviewed Kate Bast, nature and forest therapy guide and founder of Shinrin-Yoku Madison.

How to deliver hot food

It’s Friday night and your customer has been looking forward to ordering from your restaurant all day. They’re planning a night on the couch, so they quickly place an online order for delivery. You wait 45 minutes, meet the delivery driver at the door, and eagerly sit down to eat, expecting a plate of piping hot food…only to take the first bite of a disappointing, lukewarm meal. They probably haven’t followed hot food delivery best practices.

For a customer, there is almost nothing worse than paying for a delicious takeout or delivery meal only to have it arrive cold. In a First Orion food delivery survey report, 36% of respondents cited “cold food” as one of the most common issues requiring contact with customer service.

Delivering hot food hot isn’t just a matter of customer satisfaction; It is also a food safety issue. The FDA states that hot food should be kept at 140°F to prevent bacterial growth. If your restaurant is delivering food outside of the safe temperature zone, it poses a safety risk for customers.

There are several strategies companies can employ when delivering hot food to customers. The first and most obvious is better food isolation, but there’s also vehicle-specific function planning, area-specific route planning, and delivery prioritization – all of which OptimoRoute can accommodate.

Jump to the section that interests you the most:

How to keep food warm during delivery: 6 tips

You can’t expect food to stay hot just by piling cardboard boxes or Styrofoam containers into a paper bag and stapling them shut. Whether you’ve been in the food delivery industry for years or you’re looking to start a food delivery business, you can learn from these best practices for keeping food warm on the go.

Make sure hot food is wrapped separately

When hot food is packed with cold food, heat is transferred from the warmer container to the colder one. This not only warms up cold dishes (who wants to eat a hot garden salad?), but also cools down your warm dishes.

The CDC recommends packaging hot and cold foods separately during delivery to maintain temperatures. Chilled, frozen or room temperature food should always be kept in a separate bag from the hot food containers.

Keep vehicle windows down and air conditioning off

Air conditioning lowers the temperature throughout the car, affecting the temperature of everything in it – including your hot food. Instead of leaving the air conditioning on, drivers should roll down the windows. This allows them to cool down without significantly lowering the temperature of the hot food.

Use insulated bags or packets

A thermal or insulated grocery delivery bag will keep heat from escaping to the outside. Insulated pizza bags are commonly used for pizza delivery, but are useful for other types of food as well. Compared to plastic or paper bags, it’s a great option for keeping groceries warm during delivery.

Make sure each driver has enough insulated bags or packages for all their hot containers. As with any other expense, you should always keep an eye on the cost of food packaging to spare your bottom line. If you’re in an urban area and dependent on delivery drivers, you also need to consider exposure to the elements. Use insulated bags made of water-resistant material to keep food warm and protected in all weather conditions.

Add heat packs to your bags

Any dish will lose temperature slightly over time if nothing keeps it hot longer. Use heat packs to keep food warm during delivery. Put them directly into the food container bag to keep the food as warm as possible and to insulate the heat packs well.

Use a portable food warmer

Portable food warmers are a great way to keep meals warm during meal service and offer an upgrade over insulated bags or heat packs. Food warmers are easy to use and offer the best temperature control and thermal insulation of any packaging system.

They tend to be electric and require a power source, so make sure you have working 12v adapters in your delivery vehicles. You should also make sure the species you buy fits in multiple containers to get the most out of it.

Possibly wrap in aluminum foil

A heat pack, insulated bag, or portable food warmer may not be enough to keep food warm until it’s delivered to your customer’s door. Aluminum foil can provide an extra level of protection and insulation when hot food is being delivered.

Aluminum has a high reflectivity for both visible and infrared light, which means that instead of radiating heat off a food container, it reflects heat back to the container. Wrap containers in aluminum foil to provide extra insulation to deliver food hot and keep customers happy.

The main culprit when hot food is delivered cold: travel time

Photo by Mikhail Nilov on Pexels

Heat packs, meal delivery bags, and food warmers can help keep food warm, but there is a limited amount of time that food temperature can be maintained in a car or in the back of a bike. The root cause of groceries being delivered cold is too much time spent on the road during delivery. To keep the food warm, the best thing you can do is optimize the routes to get to the customer’s house faster.

According to a 2016 McKinsey study, “Delivery speed is the biggest variable for customer satisfaction, with an average of 60 percent of consumers across all markets citing it as a key factor.” And that was before the pandemic, after that demand for food delivery services and – platforms up. Now, 68% of 1,000 consumers surveyed by the National Restaurant Association say they are more likely to buy takeout or delivery than before the pandemic.

With demand increasing, it’s more important than ever for restaurants and foodservice companies to meet customer expectations and increase their speed of delivery. To do this, you need to reduce travel time; You need to optimize the routes of your delivery drivers. You can try manual calculations or route maps, but they aren’t always the most accurate and will take a long time.

To really improve delivery speeds and deliver quality meals to your customers, you need a tool that automatically calculates the fastest, most efficient routes for your drivers.

Don’t just minimize travel time: implement intelligent technical solutions to guarantee success

Photo by MART PRODUCTION on Pexels

OptimoRoute can guarantee food arrives hot and ready for your customers. Our grocery delivery route planning software helps you optimize routes, reduce delivery times and simplify your delivery process – all without manual, time-consuming calculations.

Our solution uses intelligent technical features such as vehicle-specific function planning, area-specific route planning and delivery prioritization to ensure orders arrive as quickly as possible and at just the right temperature for safe enjoyment.

Vehicle-specific function planning: plan your deliveries with the most suitable vehicle and delegate the delivery of hot meals to vehicles with built-in heating. The software allows you to pre-assign vehicle functions and specify which are heated (or alternatively frozen food storage capabilities). You can then automatically assign hot food to heated vehicles to keep food warm on the go.

Area-Specific Routing: OptimoRoute’s software helps keep deliveries within specific geographic areas using geofencing. One of the biggest time wasters for delivery drivers is placing orders on opposite sides of town on the same trip; Driving back and forth is time-consuming and inefficient, and hot food gets cold in the meantime. To better optimize delivery routes and times, use software like OptimoRoute to assign specific delivery zones and group orders based on those zones.

This type of route planning is becoming increasingly important as the grocery delivery industry grows and evolves. According to the latest OptimoRoute delivery data, there has been a drop in orders for individual drivers (34%) but an increase in kilometers traveled (43%), suggesting companies are now covering larger metropolitan areas. With geofencing, you can ensure each driver stays in their zone to deliver orders and efficiently manage delivery routes across larger coverage areas. Your customers get their food faster, and the food stays warmer, safer and ready to eat.

Delivery Prioritization: OptimoRoute’s delivery prioritization feature allows you to set time-based priorities, allowing you to increase delivery speed for high-priority orders. Hot meals should be a higher priority as you don’t want to risk the food getting cold along the way. Set time-based priorities for hot food so your drivers deliver those food orders first and the customer gets the food while it’s still hot. Orders with lower priority are delivered later because they can remain in the vehicle longer.

With these smart features, OptimoRoute guarantees food arrives hot and ready to eat, as if your customers were sitting in your dining room. Our solution is scalable for businesses of all sizes, from local food suppliers and grocery stores to larger food delivery companies that need to streamline last mile delivery. Take ownership of in-home delivery by planning and optimizing grocery delivery routes to reduce travel time and keep groceries warm.

Do you want to offer food delivery but aren’t sure how to go about it? Learn more about why delivery is a necessity and how to choose the best delivery service for your restaurant.

People who use self-heating hotpots, a popular new product, risk scalding and even injury in explosions, the Shanghai Consumer Council warned on Tuesday.

Hu Min / SHINE

Hu Min / SHINE

People who use self-heating hotpots, a popular new product, risk scalding and even injury in explosions, the Shanghai Consumer Council warned on Tuesday.

The hotpots contain heat packs that activate when water is added – the ingredients are then steamed.

The products have become a hit because of their convenience, council officials said.

The sales volume of self-heating stews during the annual Singles Day shopping spree in November last year reached 4.53 million, more than doubling the sales figure of 1.7 million in 2017, the council said.

However, there is no industry standard, which raises security concerns.

The council conducted tests on 20 self-heating hotpot products purchased both online and offline, priced between 16.9 yuan (US$2.5) and 49.9 yuan. The tests included temperatures, gas released after activation and the contents of the heat packs.

“Tests showed that the heat packs gave off hydrogen, a flammable gas, and the amount of hydrogen was huge,” said Shang Zhaocong, deputy director of the National Chemical Product Safety and Quality Supervision and Testing Center.

According to Shang, one pack of hotpots produces about 40 liters of hydrogen.

“Eating a hotpot in an enclosed space like a car or a room with closed windows creates hazards,” Shang said.

“If people start the car or smoke after eating two packs of the food, there is a risk of an explosion because a 4 percent concentration of hydrogen in the room will trigger a combustion.”

The tests also revealed that the highest temperature one of the hotpots reached was 121.9 degrees Celsius, posing a risk of scalding, Shang said.

In addition, the packs of six samples deformed during use.

The council suggested that the competent authorities draft a standard that covers both safety requirements and product warnings.

The council warned consumers not to use the hotpots in enclosed areas and classify them as hazardous waste.

Self-heating food packages are active packages with the ability to heat food contents without external heat sources or electricity. Packages typically use an exothermic chemical reaction. Packages can also be self-cooling. These packs are useful for military operations, natural disasters, or when conventional cooking is unavailable. These packets are often used to prepare main dishes such as meat dishes that are tastier hot.

chemistry [edit]

Self-heating rice with quicklime and water as the heat source, consumed before adding water to the quicklime

The heat source for the self-heating can is an exothermic reaction that the user triggers by pressing the bottom of the can. The can is manufactured as a three-walled container. A container for the beverage surrounds a container with the heating medium, which is separated from a water container by a thin, frangible membrane. When the user presses the bottom of the can, a rod pierces the membrane, allowing the water and heating medium to mix. The resulting reaction releases heat and thus warms the surrounding beverage.[1]

The means of heating and the reaction responsible vary from product to product. Calcium Oxide is used in the following reaction:

CaO(s) + H 2 O(l) → Ca(OH) 2 (s)

Copper sulfate and zinc powder can also be used, but this method is less efficient:

CuSO 4 (s) + Zn(s) → ZnSO 4 (s) + Cu(s)

Anhydrous calcium chloride is also often used. There is no chemical reaction, instead heat of solution is generated.

Commercial heat sources for self-heating food packaging use an exothermic (heat-releasing) reaction for which there are several common formulations. These include:

Quicklime aka Calcium Oxide and Water. Quicklime, inexpensive and readily available, is generally recognized by the FDA as safe. [2] The product of the reaction is calcium hydroxide.

The product of the reaction is calcium hydroxide. Finely powdered magnesium metal alloyed with a small amount of iron and table salt, activated by the addition of water, as in an MRE flameless ration heater.

Some newer formulations use a thermite-like reaction between a more reactive metal powder like aluminum or magnesium with a less reactive metal oxide like iron oxide or silicon dioxide [3].

draft [edit]

Self-heating cans have two chambers, one surrounding the other. In one version, the inner chamber contains the food or drink and the outer chamber contains chemicals that undergo an endothermic reaction when combined. When the user wants to heat the contents of the can, a ring on the can—when pulled—breaks the barrier that keeps the chemicals in the outer chamber away from the water. In another type, the chemicals are in the inner chamber and the beverage surrounds them in the outer chamber. To heat the contents of the can, the user presses down on the bottom of the can to break the barrier separating the chemical from the water. This design has the advantage of being more efficient (less heat is lost to the surrounding air) and reducing excessive heating of the product’s exterior, which can cause discomfort to the user. In either case, after the heat of reaction has been absorbed by the food, the user can enjoy a warm meal or drink.

See also[edit]

References[ edit ]

Further reading[edit]

How to make a homemade heating pad without rice?

If you don’t have rice, you can make a homemade heating pad by stuffing dried beans into a clean cotton sock. You can also place a wet washcloth in a microwave-safe freezer bag and heat it in the microwave. Simply wrap the pack in a towel and apply to your sore muscles for 15 minutes!

If you’re old fashioned and don’t have a microwave, you can also put a damp towel in the oven at 300F. Only leave it in for about 5 to 10 minutes depending on how thick your towel is! From there, you can carefully remove it from the oven, let it cool if it’s too hot, and use it!

Disclaimer: These methods should only be attempted by adults and require extreme care to avoid being burned or injured.

Description: This phenomenon uses a supersaturated solution of sodium acetate. Clicking on the metal disc releases a small number of sodium acetate crystals which serve as nucleation sites for the sodium acetate to crystallize into a hydrated salt. Energy is released from the crystal lattice. The heat pack can be placed in boiling water and the sodium acetate redissolved. This phenomenon shows how binding energy can be released. It also shows the importance of chemical engineering and could lead to a section where students design their own device (or application).

Web Resource: Chemical Heat Pack – Wikipedia, Snappy Heat – Amazon

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Article overview

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To make a rice sock, you need a 100% cotton sock with no metal or synthetic materials inside so it won’t burn in the microwave. Open the sock and fill it ¾ full with uncooked rice. Then tie the empty part of the sock in a knot to secure it, or tie a piece of string around the end of the sock. Microwave the sock on high for 1-2 minutes. Keep an eye on it as it heats in case it starts to smoke. Allow the sock to cool for 10-20 seconds, then remove from the microwave and place on your sore muscles for relief. After it cools, reheat the rice sock if you like. If you want to learn how to freeze the rice to make a cold pack, keep reading the article!

How to make a homemade heating pad without rice?

If you don’t have rice, you can make a homemade heating pad by stuffing dried beans into a clean cotton sock. You can also place a wet washcloth in a microwave-safe freezer bag and heat it in the microwave. Simply wrap the pack in a towel and apply to your sore muscles for 15 minutes!

If you’re old fashioned and don’t have a microwave, you can also put a damp towel in the oven at 300F. Only leave it in for about 5 to 10 minutes depending on how thick your towel is! From there, you can carefully remove it from the oven, let it cool if it’s too hot, and use it!

Disclaimer: These methods should only be attempted by adults and require extreme care to avoid being burned or injured.

Hot and cold packs: A thermochemical activity

Crystal Risk

Product developer

A discussion of chemical hot and cold packs can really warm up a thermochemistry lesson. In the following activity, students will use a coffee cup calorimeter to measure the heat of solution of a chemical salt of 3 different masses. For safety reasons – and for a more environmentally friendly chemistry experience – it is recommended that students use ammonium chloride for the cold packs and calcium chloride for the heat packs. If chemicals are limited, consider having half the students work with one chemical and half with the other. After the students have measured the heat of solution for the 3 masses, they plot their data (temperature change vs. mass) and draw a regression line. The best fit line can be used to determine what mass of chemical is needed to reach a given temperature. Students then design a heat and/or cold pack that uses 100ml of water and can be activated when needed. Make sure you review student designs before allowing them to complete the activity and that students understand and follow appropriate safety protocols.

background

calorimetry

Calorimetry is the science of measuring heat. In many chemical and physical transformations, energy is transferred in the form of heat. The magnitude and direction of the heat can be determined using a calorimeter. In reactions that take place in aqueous solutions, the energy is transferred to or removed from the water. A calorimeter is a device that is insulated, preventing heat from flowing in or out of the system. Since the experiment is carried out under constant pressure (atmospheric), the measured change in water temperature is due to the reaction enthalpy (heat of reaction). The heat of reaction can be calculated from the measured values ​​for the change in water temperature.

The heat transfer or enthalpy change in a reaction (q rxn ) is related to the mass of the solution (m), the specific heat capacity of the solution (c), and the temperature change (ΔΤ = Τ final — Τ initial ).

q rxn = – (m × c × ΔΤ)

The specific heat capacity of a substance is the amount of energy required to heat 1 g of substance by 1 °C. The specific heat capacity of water is 4.186 J / (°C × g). In experiments in aqueous solution, the specific heat capacity of water is generally used.

Instant hot and cold packs

Many instant hot and cold packs work by dissolving a salt in water. As the salt dissociates, heat is either released in an exothermic reaction or absorbed in an endothermic reaction. Commercial instant cold packs typically use either ammonium nitrate or urea as their salt component; Heat packs often use magnesium sulfate or calcium chloride. These reactions work in a similar way. When the salt is dissolved in water, the ionic bonds of the salt break. This process requires energy, which is obtained from the environment. The ions then form bonds with the water, a process that releases energy. If more energy is released than absorbed, the process is exothermic, making the solution feel warmer. When more energy is absorbed than released, the process is endothermic, making the solution feel cooler.

There are two other types of instant hot packs that are commonly sold commercially. You heat up when you’re exposed to air. This hot pack works because iron reacts with oxygen to form ferric oxide, an exothermic reaction. The other type is based on the supercooling of sodium acetate. When the solution is heated, it can become supersaturated. Without a seed crystal, the sodium acetate remains in solution on cooling. This type of heat pack typically contains a metal disk that when depressed provides a site for crystallization. As the sodium acetate forms a regular crystal arrangement, heat is released. This hot pack is reusable as it can be regenerated in boiling water to form the supersaturated solution again.

security

Use this activity only in accordance with established laboratory safety practices, including appropriate personal protective equipment (PPE) such as gloves, chemical goggles, and lab coats or aprons. Ensure students understand and follow these practices. Know and follow all federal, state, local, and school district regulations for laboratory waste disposal. Students should not eat, drink, or chew gum in the lab and should wash their hands before and after entering or exiting the lab.

Materials (per student group)

calcium chloride

ammonium chloride

3 styrofoam cups with lids

Mug 400ml

Mug 150ml

Measuring cylinder, 100 ml

water

thermometer

hot plate

balance

boats weigh

Various materials for making thermal packs (as indicated in students’ designs)

procedure

activity 1

Place 1 styrofoam cup in another, then place both cups in a 400ml beaker. This is your calorimeter for measuring temperature changes. Measure 100 mL of water with a graduated cylinder and pour it into the top polystyrene beaker of the created calorimeter. Place the lid on the calorimeter and pull back the tab to create an opening. Insert a thermometer into the calorimeter through the opening in the lid. Stir the water with the thermometer and monitor the temperature until it stabilizes. Record this temperature (±0.1 °C) as the starting temperature. Measure out 5 g of the chemical salt. Note the exact value used. Remove calorimeter lid, add 5g chemical salt and stir. Replace the lid and thermometer. Continue stirring and monitor the temperature for 2 minutes. Record the highest or lowest temperature reached (±0.1 °C) as the final temperature. Discard the solution as instructed by your teacher and rinse the inner cup. Thoroughly dry the calorimeter device before reuse. Repeat steps 1 to 8 two more times with 10g and 15g chemical salt respectively. Determine the temperature change.

ΔT = T f − T i

Graph the change in chemical salt temperature versus chemical salt mass. Draw a best-fit line for the points. Optional Data Analysis: Calculate the heat absorbed by the water for each mass of chemical salt and the heat absorbed by the calorimeter for each mass of chemical salt. The specific heat of water is 4.186 J/°C × g.

qω = – [cω × mω × ΔΤ]

Calculate the enthalpy of solution for each mass of chemical salt.

activity 2

Design a portable, single-use heat pack or a cold pack to treat injuries. The pack must contain 100g of water separated from a solid chemical and only activated when the user does something with the pack to mix the two components. Your task is to determine how many grams of chemical it takes to reach the following temperatures: hot pack, 55 °C (131 °F); Cold pack, 3°C (37°F).

Below is a guide to creating your thermal pack. Make sure you understand how your teacher expects you to present your designs.

Draw your hot or cold pack. Add labels to indicate sizes and quantities of materials used. List all the materials and quantities needed to make your thermal pack. Explain the steps you will follow to build your thermal pack. Describe the safety precautions you will use when creating and testing the thermal pack. Explain how you will test your heat or cold pack. Think about how you know if you’ve been successful. Get your teacher’s approval to construct your heat pack. Construct your thermal pack. Note any changes you make to your design during construction. Test your thermal pack. Record any data you collect. Explain if your design was successful and what changes or modifications you would need to make if you were to do this activity again.

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