I have been using exhaust heat from my fenton headers to aluminum dual intake for many years on my daily driver.
I am in the CA high desert and drive often across the desert freeways including mountain climbs in the middle of summer for hours and never had a problem with overheating of the engine or intake.

All you have to worry about these days is too much ethanol blend in the gas, when you park after a hot run and it wants to boil over.
But even that is not a real problem and water or exhaust wouldn't make any difference there.

I prefer exhaust heat cos it heats up my intake quicker during the freezing months up at altitude.