In addition to what others have written, note that the temperature limits are for the device, not for ambient air temperature. Your wrist acts as an heat sink, so the watch is never going to get significantly hotter than skin temperature. The limit temperatures would require something like an hair dryer blasting full at the watch on your wrist for an extended period of time, and that sort of thing would burn your skin before the watch got damaged.
Leaving it on the dash of your car in the Sun on an hot day … that would be bad for the watch. But resting your arm on the window while wearing the watch? Just fine.
b&