the hottest was 108 and about 95% (official temp)
but the hottest I've ever been in (for extended times) was when I had heatstroke (1992 i think) it was 106 for the high temp and I was building a stainless steel tank (30' dia x25' tall no roof yet). a bit before noon, my stereo quit working, so I finished up what I was doing and was leaving the tank to check on the cord and get a drink, went to wipe the sweat off me and there was none. made it maybe 30' out the hatch before I blacked out. they tell me I was in some sort of seziures when they found me (my body was basicly one big cramp).
when I returned a couple days later they showed me my stereo. it was your standard black plastic boom-box, I'd had it sitting on a 5-gallon bucket in the center of the tank. it looked like hell. the plastic had softened and the speakers had sagged down over the sides of the bucket.
I guess the reflective stainless just consentrated all the heat to the middle, kinda like one of those solar cookers you see for sale.