If a client calls in saying a device is overheating and not working properly, take the following steps.
Ask the client how they know the device is overheating
If their answer is the device is hot to the touch and not responsive to actions it more than likely is an overheating issue
If the client has a compressed air container, have them shoot the dust out of the device to clear room for the fan to spin and cool the system.
Tell them to really get in there and try to get as much dust out as possible it will not damage the device.
After it gets air sprayed, have the client let it cool down and try to turn it on again and see how it performs for a few hours
If the client comes back and says it's working as expected, good! ticket complete, otherwise you will want to tell the client to drop off the device at our office so we can take a look at it to see if there are any deeper issues that may have stemmed from the heat or anywhere else.
Further assess when the device is in the office to see what the issue is. look for any signs of damage inside the device and boot up the device and see for yourself what is going on.