I have seen excessive heat cause all different pins to play up n reset etc.
Also, I do know first hand that the hardware (lets call it a computer just to be basic) that the hardware inside a Pinball 2000 headbox (Revenge from Mars or Star Wars Episode 1) needs a new working CPU fan to be working 100 percent, and the large power supply fan also needs to be working 100 percent or things get way too hot and the game resets.
In a heatwave, which we have also had this last 3 or 4 days in QLD, I had my SW Ep 1 reset, only to find the power supply fan which sits in the computers metal case, had shit itself. This is a large fan and it is needed. The reset did me a favour, as a NEW cooling fan for the power supply and a few little mods to keep everything chilly are on their way.
A nice air-conditioned room, is alot nicer I think for both man and machine.