You will probably be horrified to hear this but I am still using an old Telkom Marconi. A while ago it got so hot after downloading a few hundred MBs wirelessly that it stopped working. I was on the point of chucking it when I realized that it had recovered after cooling down. To solve the problem, I cut a hole in the lid and inserted an old 486 cooling fan. To cut the noise, I run the fan off an 8 volt voltage regulator. Problem solved