I'm at OKW for the week and the forecast is for high 80s/low 90s all week. I don't know where the OP's son was, but we were here yesterday and the hottest it got was 94 degrees - and that was my car's reading at the hottest part of the afternoon.
Are you sure he didn't tell you a little fib and actually went to Vegas?
Was just there and it was a "normal" 110. It's only a dryheat. Like the other's said it hasn't been out of the low 90's. Hope he enjoys his stay anyway. It's not that bad here.