I have a 20-something man who's been in a fight and was beaten up badly enough that he's either unconscious or nearly so. He's been left outside, in normal clothing (jeans/shirt) but without a coat, and the temperature is in the high 20's/low 30's. Where he's at, there's no snow on the ground. How long is he going to last out there without any sort of permanent damage/death? Someone's coming to find him, but I'm not sure how long I can give them to look.