What happens if my AED becomes very cold or hot?

The AED malfunctions. The AED indicates this by a loud beep and the LED light will flash red.

If the AED is out of order for too long, the battery will be consumed and the AED may fail. The AED performs a daily self-test. At too high or too low a temperature the test is postponed. If the test is postponed 3 times the AED tells you that the ambient temperature is too high or too low.