I use to work almost daily in those and higher temps in an industrial setting. We always had to keep an eye on the new guys until they learned to deal with the heat. We always sent them to drink lots of water and sports drinks if they started to falter. In a low humidity setting getting wet on the outside helps too depending on circumstances of course.
As I sit here looking out on a cool rainy day I don’t really miss it much but know I could survive it again if I had to. Give him our best wishes and tell him to watch the guys who have been there a while they will have learned a few tricks.
Temps like that you will never “beat” but you can learn to keep them from killing you!