Portable furnace for wearing apparel

A portable furnace for generating and circulating heat in wearing apparel or the like comprising a compact insulated case capable of being carried on a person and having a cavity therein and further adapted to be opened to receive slow burning solid fuel agglomerates in said cavity for combustion, a liquid reservoir in said case positioned for radiant heat transfer from ignited fuel agglomerates in said cavity to a liquid in said reservoir, a flexible liquid conduit having both ends thereof connected for circulation of the heated liquid from said reservoir through said conduit in a closed circuit adapted for circulation of heated liquid from said reservoir through said conduit, and pump means connected to said conduit for hand manipulation thereof to circulate heated liquid from said reservoir through said conduit on demand, said cavity having top and bottom walls and side walls with one side wall providing a heat exchanger for said radiant heat transfer, said side walls except said one side wall being insulated for prevention of heat transfer, said one heat exchanger side wall being lightly insulated on the inside such as to permit heat transfer through said one side wall from said cavity to said reservoir but at the same time prevent excessive moisture buildup on said one side wall which would otherwise be capable of extinguishing a solid fuel agglomerate under combustion in said cavity, and vent apertures in at least one of said top and bottom walls.