DIAGNOSIS Some warmth is normal. Excessive heat indicates a power regulation issue or a defective battery.
FIX First, check the power source. Use only the original 15W USB-C adapter and cable. Plug into a wall outlet, not a charger block for a phone. Ensure vents on the bottom are not blocked.
IF THAT DIDN'T WORK The internal 53.2Wh lithium-ion backup battery can fail and overheat. Discontinue use immediately. Contact Amazon support. Do not attempt to open the unit.
HEADS UP The battery is for clock and settings retention during brief power loss. If swollen, do not handle. This is a fire risk. Amazon will replace units with defective batteries.