With the cold, when you are in natural conditions far from home, you can and should fight. Moreover, now there are many modern and technologically advanced portable devices on the market, individual heating pads. various types and types, compact gas heaters and so on, the operation of which is based on various physical and chemical processes.

According to statistics, from 10 to 15% of people who died in natural conditions became victims. Even the warmest clothes negative temperatures air, capable of maintaining a positive heat balance the human body for only a very limited time. Sooner or later, the heat loss will be greater than the heat production and the cooling of the body will begin. Prolonged exposure to cold is dangerous. It paralyzes the will and dulls the instinct of self-preservation. This can eventually lead to at least serious problems with health, or at most - to death.

Disposable chemical heating pads and thermal packs for heating in field conditions.

The cheapest and available means individual heating are various disposable chemical heating pads (thermal packs) for hands and feet. Heat in such heating pads is usually generated as a result of a chemical reaction between the contents of the package itself and oxygen. Such heating pads are very easy to use, sometimes it will be enough to start the process of heat release by removing it from the package. Working temperature, depending on the purpose of a disposable heating pad - from plus 40 to 60 degrees Celsius. Operating time - from 4 hours or more.

The design of some disposable chemical heaters allows you to temporarily stop the process of heat release from it. To do this, it is enough to stop the access of oxygen to its active content and the reaction stops. Disposable chemical heating pads will be convenient autonomous sources of heat for fishermen, tourists, hunters and the military. They can be put in shoes, in gloves, in inner pockets of clothes, to heat equipment (photo and video cameras) when working in the cold, etc.

Reusable salt heaters for heating in the field.

Reusable salt heaters is a sealed container made of dense material, which is filled with a supersaturated saline solution. The principle of operation is based on the effect of heat release when the phase state of materials changes. Salt heating pad can have almost any shape and size. So, for example, a saline foot warmer can be in the form of an insole.

Inside the heater there is an applicator (stick or circle), with the help of which it is launched. The operating temperature of salt heaters is from 50 degrees and above. The operating time depends on the size of the heater itself and the ambient temperature - from 2 hours or more. After the end of the work cycle, salt heaters are put into working condition by placing them in boiling water for a while, after which it is again ready for reuse.

reusable catalytic heaters for heating in the field.

In addition to disposable chemical heaters, there are reusable pocket catalytic heaters. The principle of their operation is based on the catalytic flameless oxidation of alcohol or gasoline vapors, which is accompanied by the release of heat. Platinum serves as a catalyst in such heating pads. A striking example— classic pocket catalytic gasoline heating pad Zippo Hand Warmer. More details about it are written on our website.

Prevention of hypothermia in cold weather.

In cold weather, you should try to adhere to the following simple rules.

1. Generate heat.

Eat often, but little by little, and high-calorie foods. When food is taken frequently and in small portions, this increases the overall metabolic rate of the body, since more calories are consumed in the process of digestion. This in turn leads to the production more internal heat.

If necessary.

- Do warm-up exercises.
- Make fire and use reflective surfaces.
- If possible, always be located with south side to receive solar heat to the maximum.
- Drink warm or hot liquids with sweets or sugar dissolved in them.

2. Reduce heat loss.

- Wear appropriate clothing and footwear for the weather.
- Especially insulate the head and neck.
- As soon as possible, immediately change from wet clothes to dry.
- Find or make a protective cover or shelter.
– Isolate the body from cold surfaces as much as possible.
- Avoid alcohol completely.

Making a chemical heating pad

On a winter hike or a trip to the northern regions, it is so nice to warm up from an outside source of heat. But a fire can only be made at a halt or during a long stay, but what to do on the move? It can help here chemical heating pad , which is a required attribute in sets for survival.

Of course, it can be purchased in specialized stores, but it will not cost as cheaply as we would like, so it is better to stop at homemade device. Depending on how you want to use it: to warm your hands, body under clothes or as a heating pad in a sleeping bag, a container is also selected in which the chemical reaction will take place.

There are several ways to make a chemical heating pad, but we will focus on three of the most common. First, let's define the ingredients that I depicted in the picture.

Method 1 (older)

For the first method you will need: 20 g of ordinary salt (NaCl), 40 g blue vitriol(CuCl), a piece of aluminum wire and 30g sawdust. It is advisable to grind vitriol and salt to a crystal size of no more than 1 mm (if they are larger).

Add sawdust to the mixture of salt and copper sulfate and mix thoroughly. Bend the aluminum wire into a spiral and put it in a jar or bottle (preferably glass). Pour the prepared mixture on top so that the level is 1 cm below the neck. To bring it to working condition, it is enough to add 50 ml of water to the container, which will start the reaction and raise the temperature of your heating pad to 60 ° C in 3-4 minutes.

To understand the principle of action, I will give the formula for a chemical reaction:

CuSO 4 + 2NaCl → Na 2 SO 4 + CuCl 2

It is the formation of copper chloride that leads to the release of part of the heat, while the main heat occurs when it interacts with aluminum wire:

2Al+3CuCl 2 → 2AlCl 3 +3Cu

Wood chips do not take part in the chemical reaction. By absorbing water, they are a kind of reaction retardant, which significantly extends the time of the heating pad. In addition, wood has a low thermal conductivity, which allows it to accumulate heat and release it gradually. In a closed container, heat is retained for up to 2 hours.

For modern realities, glass containers are something rare. Much easier to find plastic container suitable form and volume. In this case, make sure that the wire does not touch the plastic, as it may warp when heated.

Method 2

This design of a chemical heating pad is in demand among tourists who arrange winter overnight stays in tents. They take it with them in a sleeping bag and place it in their bosoms to warm up before going to bed.

To make it, you need a dense waterproof bag (experienced ones take 2 - one in one), into which a mixture of 5 g of CuCl powder, 5 g of aluminum powder and 5 stal spoons of sawdust is poured. It is enough to add 40 ml of water to such a mixture to start a chemical reaction with the release of heat.

Method 3

This method is very similar to the first one. Only in this case we do not use sawdust.

First, take a piece of aluminum foil 20x30 cm. Fold it in half (10x30 cm) and roll it into a tube around a wooden barbecue skewer. After that, glue the skewer to the lid of the plastic bottle. glue gun. So the heated foil will not touch the plastic walls.

We take edible salt and copper sulfate powder in a ratio of 1: 2 and pour them into a bottle. To start the reaction, you need to add water to the container. During the reaction, heat and hydrogen will be released, which will have to be vented from time to time. Aluminium foil will dissolve, so the bottle must be shaken periodically. You will learn about the end of the reaction, and, accordingly, the cessation of heat release, by the cessation of gas evolution on the foil.

As you can see, the methods I have given have their pros and cons, so choose the one that suits you best for hiking and local conditions survival.

On the net you can find a lot of developments of home-made chemical heating pads for anglers and tourists. The work of the heating pad is based on a chemical reaction involving water, salt, aluminum and copper sulfate. A heating pad is used to warm up stiff fingers while fishing. You can use it to reheat cold food.
It must be admitted that the reagents are not cheap now, it is probably easier and more profitable to take a catalytic heating pad, one refueling is enough for 6-8 hours of operation, after 200-300 applications the platinum element simply changes. But, according to the author of the development we are considering, the Chinese catalytic heater has its drawbacks. If you come across a frail China, then the catalyst will last for a week. In addition, such a heating pad is sensitive to temperature. In the outer pocket, the body cools down, the fuel stops evaporating and the heating pad without fuel stops producing heat. She is capricious in this regard. Even the cover does not help. And if her frozen hands take, it will cool down very quickly.

The author of the video tutorial first demonstrates the mechanism of the chemical heating pad. To do this, he took copper sulfate bought in a store and ground it in a coffee grinder. However, he had to grind vitriol only for the sake of demonstrating the operation of the device, since large crystals crack when heated. Copper sulphate was calcined in order to increase the initial temperature of the solution, so as not to wait a few extra minutes before the reaction began, but you can do without it.

What kind of aluminum is used in the heating pad? Food foil. Width 28 cm, length 20 cm, thickness 14 microns. The ratio of copper sulfate and kitchen salt is 2:1. A bamboo skewer is glued into the cork with hot glue.

In the experiment, very cold water. The mixture is heated to room temperature by dissolving anhydrous copper sulphate. Shake the bottle with the mixture to speed up the chemical reaction. The foil on the skewer will evenly heat the liquid in the bottle. During the reaction, hydrogen and heat will be released, which will speed up the reaction. The pressure in the bottle must be controlled and hydrogen constantly vented. Aluminum dissolves and copper is released from the solution. If no gas is released within a minute, then the reaction is over. In principle, water can even be boiled, but a bottle cannot withstand such heating.

And now about how not to make a chemical heating pad.

Wanting to keep the reaction time to a minimum, the author of the video decided to increase the aluminum contact area. To this end, he crushed aluminum plates. Further, as usual, I put it in a bottle in desired proportion salt and copper sulfate. Filled with water. Stirred. I threw in an aluminum blank and screwed on the lid. Opening the lid to vent the hydrogen, he was charged with a dirty hot liquid on himself.

Watch the video experiment showing the chemical reaction behind the heating pad and how to make it yourself. Well, if you want to see right away, “what the violation of technology has resulted in”, that is, about the dangers of chemical heating pads, then from the moment 3:41.

Features of the heating pad made of copper sulphate proposed by the author.

A similar recipe has been roaming the net for decades, but it all comes down to mixing salts, adding sawdust, aluminum and water. And while not
it is clear how to regulate the reaction rate, the temperature of the heating pad and how to remove the evolved gases. The author chose the easy way. A short but intense chemical reaction produces heat, which holds the mixture of salts. This allows you to save reagents and keep the temperature in a comfortable range.
As the heating pad cools, you can add new portions of aluminum.

The rate of a chemical reaction depends on the concentration, temperature, and surface area of ​​the reactants. Therefore, aluminum in the form of foil, and not wire, pipes, corners and other things. Because the concentration of salts during the reaction falls, then there should be an excess of salts. The solubility of copper sulfate in 100 grams of water at 25 degrees Celsius is 23 grams. I do not advise taking more than 4 times the amount. during the reaction, copper is released in the form of the finest powder, which thickens the solution of salts and prevents the circulation of the solution. Copper sulphate was calcined in order to increase the initial temperature of the solution, so as not to wait a few extra minutes before the reaction began, but you can do without it.

The wooden skewer is designed to drown the roll of foil and isolate it from the walls of the bottle. Otherwise, the foil is covered with many bubbles and floats. In this case, all the heat is released in the upper part of the bottle, which leads to strong heating and deformation of the walls. In the case of a skewer, gas bubbles cause the liquid to circulate, so constantly shaking the bottle and releasing gas is not necessary. It is enough just without twisting the cork, let the bottle stand for a couple of minutes. Army units work on the same principle.
flameless food heaters.

The other is a safety heating pad, very interesting principle work in another.

When hiking, fishing, especially in bad weather, there is often a need for an ordinary heating pad. Of course, ordinary rubber is also good, but it has one significant drawback: water is heated very slowly for it at the stake. Let's try to make a chemical heating pad. To do this, we need the most common reagents.

When hiking, fishing, especially in bad weather, there is often a need for an ordinary heating pad. Of course, ordinary rubber is also good, but it has one significant drawback: water is heated very slowly for it at the stake.

Let's try to make a chemical heating pad. To do this, we need the most common reagents.

Let's start with a simple experiment. Go to the kitchen and take a pack of table salt. However, you don't need a pack. 20 g (2 teaspoons) will be enough. Then look into the locker, where all kinds of household preparations and materials are stored. Surely there was preserved after the repair of the apartment a little copper sulphate. It will need 40 g (3 teaspoons). Wood chips and a piece of aluminum wire, presumably, will also be found. If so, you're all set. Pound vitriol and salt in a mortar so that the size of the crystals does not exceed 1 mm (of course, by eye). Add 30 g (5 tablespoons) of sawdust to the resulting mixture and mix thoroughly. Bend a piece of wire with a spiral or snake, put it in a mayonnaise jar. Pour the prepared mixture there so that the backfill level is 1-1.5 cm below the neck of the jar. The heating pad is in your hands. To put it into action, it is enough to pour 50 ml (a quarter cup) of water into a jar. After 3-4 minutes, the temperature of the heating pad will rise to 50-60°C.

Where does the heat come from in the jar, and what role does each of the components play? Let's look at the reaction equation:

CuSO4+2NaCl Na2SO4+CuCl2

As a result of the interaction of copper sulfate with common salt, sodium sulfate and copper chloride are formed. It is she who interests us. If we calculate the heat balance of the reaction, it turns out that the formation of one gram-molecule of copper chloride releases 4700 calories of heat. Plus, the heat of dissolution in the initial resulting preparations is 24999 calories. Total: Approximately 29,600 calories.

Immediately after formation, copper chloride interacts with aluminum wire:

2Al+3CuCl2 2AlCl3+3Cu

In this case, approximately 84,000 calories are released (also in terms of 1 g-mol of copper chloride).

As you can see, as a result of the process, the total amount of heat released exceeds 100,000 calories per gram-molecule of the substance. So there is no mistake or deceit: the heating pad is real.

What about sawdust? Taking no part in chemical reactions, at the same time they play very important role. Greedily absorbing water, sawdust slows down the course of reactions, stretches the work of the heating pad in time. In addition, wood has a fairly low thermal conductivity: it kind of accumulates the released heat and then constantly gives it away. In a tightly sealed container, heat is retained for at least two hours.

And the last remark: the bank, of course, is not the best vessel for a heating pad. We only needed it for demonstration purposes. So think for yourself about the shape and material for the tank in which to place the heating mixture.

Salt heating pad is an indispensable thing for a wide range of applications. It is heated by the sodium acetate contained in the heating pad, which releases heat during the crystallization process. It is used during illness, when you need to warm up the chest, sinuses or ears. Salt heating pads are safe to give to children. The PVC sheath is hygienic and harmless, and it is impossible to snack on it. The internal content, sodium acetate, is a safe solution used in medicine.

The principle of operation of a self-heating salt heater

Salt reusable heating pad is a hermetically sealed polyethylene container with saline inside. Usually it is sodium acetate, which begins to crystallize when you press the button or after bending the activator stick inside the heating pad. The wand or button becomes the center of crystallization, and liquid solution begins to gradually harden, because the equilibrium of the salt solution is shifted.

During the transition from a liquid to a solid state, a catalytic process occurs, accompanied by the release of heat. Soon the sodium acetate completely crystallizes, the heating pad should be crushed by hand, and it will take any shape. The heating pad heats up to a maximum of + 54C, so it is impossible to burn yourself with it. Heat is retained for 40 minutes to 4 hours. It depends on the heater model.

The salt heater is designed for reusable. After use, bring its contents back to liquid state. To do this, the heating pad is wrapped in a piece of cloth (towel) and dipped in a saucepan of boiling water for 5-15 minutes. The crystals gradually dissolve until they become liquid. After that, the heating pad can be used again. One heating pad is designed for 50 cycles of operation. Service life up to 3 years.

Can a saline heating pad be used as a cooling compress
With bruises, insect bites, headaches, a salt heating pad can be used as a cooling compress, because it is 3 times better than ice keeps cold. To do this, you need to put the non-activated heating pad in the refrigerator for half an hour. In no case do not touch the activator mechanism! Also, do not place a salt heating pad in freezer otherwise the salt solution will begin to self-crystallize. After 30-40 minutes, remove the heating pad from their refrigerator. She is ready for use.

When Should You Use a Salt Heater?

• In the treatment of acute respiratory viral infections, with heating of the sinuses, with bronchitis.
• Apply to the ear of a child with otitis media, without fear of burns or overheating.
• With colic and bloating in a baby.
• During sinusitis.
• Put on the chest with mastitis.
• Warming up the back with sciatica or arthritis.
• Warming up muscles in athletes before competitions.
• To warm the limbs with frostbite.
• With cervical osteochondrosis or neuralgia.
• With insomnia or vegetovascular dystonia.
• You can put the baby in the stroller while walking.
• For knee pain.
• On a camping trip or fishing, when you need to warm up.

1. Do not heat up the heating pad microwave oven, and also when you put the heating pad in boiling water, be sure to wrap it with a cloth so that the polyethylene sheath does not get damaged on the walls of the hot pan.
2. If the crystallized heating pad does not fit completely into the pan, do not attempt to bend it. Boil one side first, then flip the heating pad over. After softening, it will completely fit in the pan.
3. Do not touch the heating pad with piercing objects. If it leaks, throw it away.
4. If the heating pad was placed in the freezer and self-crystallized, first heat it to room temperature, and only then boil it.
5. A salt heating pad may accidentally self-crystallize when struck or dropped.
6. Infants or toddlers with skin diseases put a heated heating pad wrapped in a layer of cloth.
7. If the heating pad has the shape of an insole, then it has a medicinal purpose and is not intended for walking.

When not to use salt water heater

Despite the wonderful consumer properties, the heating pad has some contraindications:

1. Do not use a salt heating pad during critical days and other types of bleeding.
2. You can not use it in gynecological diseases (uterine fibroids, ovarian cysts, endometrial polyps).
3. Do not use heating inflammatory processes(cystitis, pancreatitis, appendicitis).
4. Do not apply a heating pad to areas of damaged or inflamed skin, as well as infectious diseases skin.

Overview of self-heating reusable salt heaters

Salt heating pad Delta-Therm. It is designed for children and has the shape of a bear cub. It is a hypoallergenic PVF film and sodium acetate inside. Salt crystals heat up in seconds, the heating pad does not harden. Does not cause skin irritation. Can be applied to baby's tummy or ear.

Salt heating pad "ENT" Lintub. It has the shape of a human lung. Can be used by a child. Well warms the sinuses of the nose of an adult. It has a comfortable anatomical shape.

Salt reusable self-heating heating pad "Belka and K" in the form of a Christmas tree. It can be used both for heating (sinusitis, sciatica, otitis), and for cooling tissues (bruises, migraines, bites). Sodium acetate begins to crystallize after pressing the activator membrane. Heats up to +54C. An indispensable thing in hiking trips.

Salt heating pad Orlett. Keeps warm up to 4 hours, cold - up to 2 hours. Has the shape of a mattress. Can be used to treat back pain.

Salt heater-collar "Novomed". It has an anatomical shape, convenient in the treatment of cervical osteochondrosis. The heat is enough for exactly one session - 45 minutes. In a heating pad, you can move around and do everyday things.

Video: reviews and tests of salt heaters