by Gerald Rowan
There’s a really old idea that bears being recycled. In the past, when the ice thickness on lakes and ponds was more predictable, ice fishing was a popular winter sport. The problem with ice fishing is that staying warm can be challenging, with long days standing on ice out in a cold wind. The solution for many was to use a catalytic hand warmer in combination with a hooded sweatshirt to stay warm while out on the ice. The hand warmer was placed in the front pocket of the sweatshirt, and a windproof layer was added over that. The windproof layer protected the wearer from the cold wind but also helped retain as much heat as possible.
Catalytic hand warmers are still used, although battery-operated and chemical-based warming packets have pretty much replaced them. Catalytic hand warmers “burn” lighter fuel (naphtha) not with an open flame but with a catalyst to oxidize the fuel without an open flame. These warmers are made of several parts. There’s a tank or reservoir containing a supply of fuel. A wicking system gets the fuel up to the “burner” housing the catalyst. The burner is, in turn, protected by housing. The catalyst is lit and the cover replaced. The cover protects the unit when in contact with clothing. Since there is no open flame, the unit can be carried in a pocket. Some warmers use some kind of a damper to regulate the amount of air allowed into the unit. The more air, the more heat; less air, the cooler the unit will burn. Shutting off the unit is usually accomplished by cutting off all the air. Once the unit cools below the oxidation temperature of the fuel, it’s out. The warmers are hand sized and fit comfortably into pockets.
There are 2 more components you will need. One is a heavyweight, quarter-zip, hooded sweatshirt with a front pocket. Zipping or unzipping the sweatshirt allows the wearer to regulate how much heat the sweatshirt captures. The front pocket is where to place the hand warmer so it’s close to your body’s core mass and also where you can warm your hands. The shell you’ve created makes you windproof and helps trap as much heat as possible.
Most hikers, backpackers, and trekkers already have hoodies. To my knowledge, the only company still making catalytic hand warmers is Zippo (which, incidentally, is a Pennsylvania company). The hand warmers sell for about $12, while the complete kit sells for about $20. They are really long-lasting; my last one lived for about 35 years. New ones should have a lifespan of about the same length. The only part that wears out is the head containing the catalyst, which can be replaced for about $10.
Most catalytic hand warmers have a burn time of about 6 hours on a full tank of fuel. Add a small extra fuel container the size of a hip flask and you’ll extend the burn time to about 24 hours. A space blanket (mirrorized Mylar survival blanket) and a hand warmer should be in every outdoor trekker’s winter backpack.