Set tire pressure when unit has been sitting and tire are not hot. DO NOT EVER 'bleed off' air as this can lead to underinflated tires once they cool back down. Elevated pressure from tires getting hot is NEVER a problem and actually helps keep the tire from getting even hotter by minimizing flexing of the rubber at speed. Tires have to be grossly overinflated for there to be even the remotest possibility of a blowout from pressure. Tires blow out because they have been weakened from underinflation and the accompanying overflexing of the sidewalls. Go by the RV manufacturer's recommendation for pressure. The maximum safe cold temp is on the sidewall and can always be safely used but that is usually higher than what the RV mfg. calls for and will give a rougher ride. That pressure rating takes into account that the pressure will rise as the tire gets hot (but will return to the set pressure when cool again).