Salt hand warmer

When the cold season arrives, there are more and more situations when we want to get warm or at least be able to warm our hands, feet and other parts of the body. It is for such cases people have invented warmers that can help in this, especially when there is no possibility to stay in a warm room for a long time. For example, for use in field and camping conditions or when performing work associated with long-term stay in the cold, as well as for tourism and fishing. There are several types of heaters: electric, water, chemical or salt. Now in Ukraine especially became popular salt warmers, as their effective work does not depend on the availability of electricity or access to hot water. Salt warmers can be bought now in many online shops, and the video with the title “handmade salt warmers” is gaining a lot of views in social networks.

What is a salt warmer?

A chemical warmer is a reusable salt warmer filled with a concentrated salt solution (sodium acetate), capable of self-heating and releasing a large amount of heat in the process of changing the aggregate state of this salt solution during activation.

Advantages of salt warmers:

1. Efficient working result is independent of the availability of hot water and electricity
2. Suitable for multiple use
3. Holds the set temperature for about 2-3 hours
4. Mobility (can be carried in pockets or placed under clothes)
5. Cost-effectiveness.

The salt hand warmer is as universal as possible. It can be put in gloves, in pockets, put under clothes. The chemical hand warmer is small in size and weight, which allows you to use it in various conditions. It does not take up much space in your luggage. In addition, you can even make a salt warmer with your own hands.

How to make a salt warmer?

Handmade salt warmers can be made from sodium acetic acid and distilled water. For the preparation will be suitable as sodium acetate 3-water, and anhydrous.

To begin with, let’s consider the process of preparing salt warmers from sodium acetic acid anhydrous. To do this, we take:

• Sodium acetate anhydrous – 1 kg
• Distilled water – 660 grams
• Cooking vessels (stainless steel) – 2 pcs
• Stirring spoon (stainless steel) – 1 pcs
• Kitchen scales – 1 pcs

Put the cooking vessel on the scales and weigh it. Then pour 660 g of water and pour in 1kg of sodium acetate anhydrous. All this put on a water bath and start heating on medium heat, stirring constantly. It should be heated to a temperature of 70-80°C or higher. All crystals of sodium acetate should dissolve and the solution should become transparent. If you have heated the solution to more than 90°C and the crystals are not completely dissolved, then you should add some water (up to 5% on average).

Then remove the container with the salt solution from the water bath and weigh it. The weight should be the same as at the beginning of heating, namely 1660 grams without taking into account the weight of the container. Due to the fact that up to 5% of the water is evaporated during the heating process, the weight is likely to decrease. In this case, add the missing amount of water and stir the solution well. If the solution becomes cloudy, heat it again until it is clear.

IMPORTANT! For correct operation of the warmers the solution must be clean (without mechanical impurities), transparent and have the necessary proportion.

The salt solution is poured into special plastic bags (doy-paks), the activator is put in – a metal element which starts self-heating of the warmer when it vibrates.

The process of preparation of warmers from sodium acetic acid 3-water is generally similar. The only exception is that less water is added when heating on a water bath. Namely, about 5% of the total amount of sodium acetate (on average for 1kg of sodium acetate 50-100g of water), depending on the intensity of water evaporation during heating.

How to use a salt warmer

The liquid salt solution in the chemical warmer is in a state of thermodynamic equilibrium. That is, its physicochemical properties remain unchanged under certain isolated conditions. In order to activate the heating pad it is necessary to remove the salt solution from this state of equilibrium. This is done with the help of the activator – spring, coin, stick, etc., which is put in the package with the warmer. It should be bent, clicked, pressed and thus activate the composition of the chemical heating pad.

The activator then becomes the centre of crystallisation and the beginning of the transition of the salt solution from liquid to solid state. This process occurs with the release of a large amount of heat and the heating pad is heated to a temperature of about 50°C.

How long does a salt warmer last? On average, the action of the heating pad lasts 2-3 hours with a gradual decrease in temperature. What can be warmed with a salt heating pad? All parts of the body, it is especially effective in warming frozen hands and feet. In some extreme conditions, such a small heating pad can literally save a person’s limbs, and sometimes even his life.

In order to start the reverse process, the salt heating pad should be heated to room temperature, then wrapped in a cloth or towel and placed in boiling water for 10-20 minutes, it becomes liquid again. After cooling down at room temperature, the heating pad is ready for the next use.

Precautions

Due to the fact that the basis of the salt heating pad is a chemical substance and its use is associated with high temperatures, certain safety precautions should be observed:

1. To warm sensitive skin areas, the heating pad should be wrapped in a towel or cotton cloth to avoid burns.
2. Do not use the heating pad on injured or damaged skin.
3. It is forbidden to use a microwave oven to heat up salt warmers.
4. Attempting to fold the heating pad in a solid state may cause the package to rupture.
5. If the contents of the heating pad come into contact with skin and mucous membranes, flush these areas with plenty of water.
6. When using a salt heating pad for therapeutic purposes, it is necessary to consult a medical specialist.
7. The warmers should be stored at room temperature, avoid direct sunlight.