It all started with a cold, wet keister. Back when he was an Outward Bound instructor in the 1980s, Rob Hart got sick of sitting in snow caves and invented the Crazy Creek chair, a nifty clamlike contraption that instantly unfolds from a flat square into a surprisingly cozy seat.
Now another, far more serious, cold body part has again sparked Hart's inventive mind. In 1997, while descending from a winter attempt of Nepal's 22,350-foot Ama Dablam, Hart severely froze his hand. He sustained nerve damage and, with frostbite leaving him particularly susceptible to cold, feared he'd be stuck inside all winter -- motivation enough to develop a new kind of hand-warming device.
"Often when hands get cold, its because they're not getting enough blood flow," says Hart. Working with that concept in mind, Hart's Crazy ThermaBand straps around your wrist, holding a small heat packet against the radial and ulnar arteries. The heat keeps the arteries from constricting, allowing more blood flow to the fingers. So, do they work? "I was skiing that same winter wearing them," Hart says, "and the following season, I went ice climbing." Wonder what appendage he'll need to warm next. ($7; 800-331-0304)