I think the rule with electronics and high temps are if you are using them at the time. Ambient too high and they won't cool properly and go phht !! All the smoke escapes.
If they are just sitting in a hot ob unpowered I don't see a problem as long as they aren't drowning in humidity. What happens to other components, plastic and the like is another issue all together.
As an earlier poster has said, plenty of ventilation, some shade mitigation and insulation can probably reslve most problems.