If your router is hot to the touch, it could be a sign that a firmware update is needed. If that doesn’t do the trick, you might need to add a cooling element—especially if you’re working it hard.
Generally, you want router temperature below 90 degrees Fahrenheit.
Firewall rules and running a P2P client push a router CPU and generates heat. It’s just like a PC, except most router builds—especially older models—aren’t designed with cooling in mind. Heat is bad. It affects performance in the short term by slowing connection and dropping signal. In the long term, it reduces the life of your device.
A more permanent solution is placing a small laptop cooling pad underneath. Essentially a horizontally aligned fan encased in a thin chassis, it extracts hot air from underneath the router and blows it sideways. It is powered over USB, so if your router has an open port it is easy to set and forget.
If you want to blow air and time on a hot router, mount a PC case fan to the chassis with super glue and hand-wire it to a 15 V or 12 V AC adapter. You will need a soldering iron to attach inputs to the copper wiring. You might short circuit the router or shock yourself, but here’s the basic idea if you want to tinker with it:
If you want to get into this mess here’s the instructibles guide, have fun.
Monitor router temperature the easy way
Yes, the Internet of Things saves the day! A small smart thermometer will do the trick. If configuring heat monitoring using a smart phone application is more your speed, this is the route that I recommend. The Xiaomi Mini Smart Home Temperature Sensor is a small battery-powered unit that sticks on the router chassis and delivers accuracy to 0.3 degrees. Learn more
The advanced way
Network administrators keep an eye on router temperature using remote monitoring (RMON) configurations in Simple Network Management Protocol (SNMP). Routers can be monitored for heat with a remote PC. You can wire in your own temperature sensor, and routers like the Cisco 2800 series have heat sensors built in already. You still need to code in temperature tracking using the command line interface; do this yourself or find something on GitHub. A good open-source router does this as well for a lesser cost. Flash the firmware and you’ll use SSH or Telnet protocol to access the CLI, input coding with your WRT language of choice, DD-WRT, OpenWRT, Tomato, and the like.