I thought the same thing because I didn't start having the problem (had it installed, running successfully with no problems for a couple of months) until we had a really hot week upper 90s Fahrenheit. And I'm sure it's even hotter in my garage.
(I live in the Bar Area, CA, USA)
However, it gives me trouble in the mornings sometimes too when it is not hot at all - maybe like around the 70s.