Patrick Obrist has been sweating all night, curing in his own body heat.

"I feel like I have a hangover," he says, as he steps out of his concrete room that turned into a Dutch oven last night. The generator wasn't working, which meant no air conditioning. The night slipped by and Patrick rolled under the fuzzy blanket of Chadian humidity. "You sweat so much you become dehydrated," he says. It's been averaging close to 110 degrees in...