This is the best thing to train in mate,
I have spent a fair deal of time up to 4 hours out in 85-90 degree weather in my shed/gym.
The key is you need to have someone who'll keep giving you sips of water every 5 minutes.
I have found ya it is great to train longer than five minutes but if you want to be safe you need to limit to that period of time if that is what the round length is going to be.
It sorta sucks for me when I put on my gloves, I can't open a bottle of water...maybe get one of those pull-tab mouth deals.
Throughout life there are bumps along the way some may be painful...others not...who gives a damn in the end you'll still die