Faced with the cold, it is of course necessary to have adequate equipment (you can find tips for extreme cold / Arctic area here)to conserve heat and evacuate perspiration or moisture. In addition, several accessories can bring you more comfort or ensure your safety.
Disposable heaters are really useful for sensitive people at the ends, ofwhich I am a part (used at the North Pole, Mont Blanc, skiing, Poland, Czech Republic …).
Disposable heaters are essential accessories for all outdoor sports, outdoor professional activities or simply cold-sensitive people. They produce at the desired time a fast and efficient heat. Lightweight, inexpensive, they are single-use. They work thanks to a chemical reaction with air, usually redox,as soon as they are in contact with it. Their use is very simple: open the packaging, shake the sachet energetically (the longer the brewing of the crystals is prolonged and dynamic, the more intense the reaction and the more the heater heats). The heat will then diffuse for several hours, from 5h to 8h on average,at a temperature close to 55 ° C to 60 ° C for the hands or the body or 40 ° C for heaters for the feet. Odorless and non-toxic, they do not stain clothes.
In the classic uses I recommend, you can slip them into your gloves,into your shoes, into an internal net pocket of your jacket or into your sleeping bag. For the feet,be careful not to use heaters for hands,which reach considerable temperatures (55 ° C – 60 ° C) not compatible with the enclosed space of the shoes (rather at 40 ° C). There are also heaters in the form of soles, very useful for shoes. Adhesives can be used for a sleeping bag or jacket.
Be careful, some heaters should not be in direct contact with the skin,which does not always make them very practical; others cannot be placed in a sleeping bag or pocket; always check the instructions for use before use.
The average cost is from 1€ to 4€ for a bag of 2 heaters. You can also buy them in boxes, which is cheaper.
There are two types: chemical heaters and combustion and/or coal heaters.
Chemical heaters consist of a metal spring placed in a bag containing a chemical substance. When the spring is "clicked",the heat is released for almost 1 hour,reaching a temperature of 50 ° C on average. The heater regenerates by immersing it in boiling water,and reuses many times. Average price: 7€
Coal hand warmers consist of a metal box,insulated internally by fiberglass in which a solid fuel of coal is consumed, inthe form of a stick. To use it, it is enough to light the stick with a lighter,let it burn like an incense stick for more than a centimeter,and place it in the hand warmer. It will release heat by consuming for 3 hours to 4 hours,at a temperature of about 40 ° C. This type of product is not suitable for children. Average price: about 9€ for the hand warmer and 4€ for 12 coal sticks.
Gasoline hand warmers work by burning lighter gasoline, without flame, in catalysis. A filling of gasoline ensures about 10 hours of heating, at about 50 ° C. This type of hand warmer is not suitable for extreme sports,because it is difficult to bear to be turned over, the gasoline can leak.
The so-called "survival" blankets are very useful to protect yourself from the cold. Their use is twofold,and can also protect from excessive heat: by placing the silver surface outside, it returns the heat rays, isolates heat,and allows air conditioning of tents, caravans, cars … By placing it inwards, the silvery surface isolates moisture, cold, rain, soil,and retains body heat. Chosen fine, it will rather be used for extreme situations and help (high assembly, great cold); thicker, it will be usable for hiking,and washable for prolonged use.Its ultimate shape is that of a sleeping bag, extremely practical because it weighs on average only 50g. Average price: 4€ to 6€