Mad Dogs and an Englishman

Death Valley in California is the hottest place in the western hemisphere. Not even mad dogs go out there. Q.E.D. follows Gary Shopland's attempt to run 20 marathons in 20 days in temperatures of up to 1360F. Monitoring his physical and mental reactions to these extreme conditions were a physiologist, a paramedic and a sports psychologist - If mad dogs don't, then what makes Gary run?