Straight salt - delicious!! (Suck off them pretzels, slurp...)
Bananas, too.
Gatorade but I can't drink it straight either.
And I back off, big time. The first thing to go when it's hot is my motivation - somewhere down in my legs. Mental motivation I will argue with, but when the mind is ready to go and the legs won't on the third request, I stop asking and go the speed the legs request. (Which has got me thinking I may have made a mistake riding the heavy bike - normally it's an appropriate workout-inducer for a level 2 ride, but it's ... whew! it's 83, I'll be *warm* and not happy, but I won't fuse with the pavement...