Last time I was out it was over a hundred, but I broke weak, left after an hour and a half or so. Three years at a desk instead of on a yard, got fat and soft.
Younger days, I loved it when it was 114 and higher, now it ain't as much fun.
When I was in the Gulf, it was 140+ in the Main Space, our engine room crew did 20 minutes in, 40 minutes out. AC was a cruel joke on that antique of a ship, oh well. the gun mounts had "natural AC", i.e., leave the doors open for whatever breeze may be going through. Holds had GOOD air - ammo ship, had to have that for the explosives.
I am not in the excellent physical shape of our service members overseas nowdays, and salute them for what they have to go through. I did my time in the Middle East broiler 23 years ago, been there, done that.
I have one hard and fast rule about the range in summer time - when I run out of water, it's time to leave, period. Safety first.