Ukraine: Trench Candles and the Palmer Furnace

 Trench warfare and caving... two cold, wet, and dangerous activities, which have both inspired creative ways to stay warm.

Caver and hypothermia expert Jonathan Palmer invented the Palmer Furnace, for use underground. Cavers, especially expedition cavers, often traverse tight, wet passages, in caves which may have an ambient temperature in the 30's or 40's Fahrenheit. This is commonly followed by long periods of inactivity, sitting on cold ground, surveying new passage. This combination can easily result in hypothermia. 

Palmer's invention is a simple combination of a large trash bag and a candle. The person sits with the lit candle between their legs, and covers themselves, legs and all, with the trash bag. A small hole should be cut, so that the face is outside the trash bag, and the top of the head is inside. The bag traps air warmed by the candle, creating a cozy microclimate. Beeswax candles work best, burning for a long time at a high temperature.

In Ukraine, volunteers are making trench candles. This is an old technology, which was also used in WWI and WWII. 

Construction of a trench candle is simple. A tin can (1L paint can, cat food tin, etc) is filled with a spiral of cardboard, cut to the height of the can. A cardboard wick, cut an inch or two taller than the rim, is inserted. Melted was is poured into the tin, until full. The resulting candle will burn for 5-7 hours and produce quite a bit of heat. It can be used for light, warmth, and to heat food and drink. Trench candles with lids can also be boiled in water and used as re-heatable hot packs inside clothing.

Photo from How to Make a Trench Candle at Home

And here's a good video on Youtube, showing the trench candle-making process

News Story: Volunteers in Ukraine Make Trench Candles