An overheating TomTom device can be frustrating, and even worrisome when you're on the road. You need the GPS device to tell you where to go. Overheating is usually caused by improper ventilation coupled with exposure to sunlight, but occasionally it can be due to an overheating battery. You'll need to replace the battery in that case, but here are a few things you can try before calling TomTom support.
Unplug the TomTom from its charger. The battery heats up a lot more when the device is in use and it's charging.
Seat the TomTom in its mount; if it's laying on a seat or wrapped in something it can overheat quickly.
Remove the TomTom from direct sunlight. This can mean removing it from its mount if it's still overheating.
Open the windows, or run the AC in your car. If the ambient temperature is kept cool, you minimise the chances of the device overheating.