It actually can make a major difference because the differential shrinks quite a bit, and the rate of heat shedding is proportional to that difference. If your

It actually can make a major difference because the differential shrinks quite a bit, and the rate of heat shedding is proportional to that difference. If your device has a maximum temperature of 50 degrees (probably dictated by the battery controller), it can shed 3 times less energy at 40 degrees than at 20 degrees. From there, every degree matters: at 45 degrees, it's 1/6 and at 47 it's 1/10. These are temperatures you can easily reach in the sun, in cars, or in enclosed spaces like backpacks.