If I ride my bike home at 110 degrees in a headwind on High assist I notice the motor getting warm; three seconds touch test means case around 140 degrees. But back off slightly so the motor only produces 50 percent torque the motor is no warmer than the rest of the bike; half the torque means a quarter as much resistive heating. Las Vegas should be fine; just don't do any sustained climbs at high assist.Some Ebikes are managing heat.
To avoid over heating and potential damage many years ago the old technology was shutting off the engine and it became operational some 5-10 minutes later. Now they simply diminish the power available so people in Texas can ride but maybe with less assist. If you get no answer here ask the regional forum.