CLEANING AIR VENTS
The air vents on top of the router body should be kept free of dust to facilitate cooling. A paint brush is a good tool for this job. If your router spends its time inverted in a table, take it out from time to time, stand it right way up, brush the vents as above, then switch on for a minute or two to get a downdraft of air through the body. Most authorities advise against blowing air into the router to clean out dust.