While using WMWifiRouter, your device may become warm. Especially older devices generate a lot of heat when using Cellular to Wi-Fi sharing. Due to hardware overheating protection in these devices, the device will automatically stop charging the battery (as charging the battery also creates a lot of heat).

Generally this happens at the 48 degrees Celsius mark, though the value may differ on your device. 

There is no general solution to this problem, however there are some tricks you can use to lower heat generation and improve heat dissipation, prolonging the amount of time you can use WMWifiRouter in Cellular to Wi-Fi mode. Many of the devices that cannot run WMWifiRouter indefinitely "out of the box" can often be made to do so using these tricks:

• As soon as you are connected and using the internet through WMWifiRouter, press the power button on your device. On most devices this will turn off the screen while WMWifiRouter will continue to function. This will drastically reduce power usage (and thus heat generation), on some devices up to 50% !

• If your device has an extendable keyboard, extending it will improve heat dissipation.

• If you are using the device while not being on the move, putting the device on your desk or table upside down (the screen facing the desk or table) will improve heat dissipation.
  

• If you have placed the device upside down on your desk or table, also removing the battery cover will improve heat dissipation.

• Placing the device approximately 1 to 1.5 meters (3 to 5 feet) from the client device's Wi-Fi antenna seems to be the sweet spot for the best signal quality. Please also make sure there are no objects in the "line of sight" between the device and the client antenna. Thiswill reduce Wi-Fi power usage.

• WMWifiRouter by default sets your device's Wi-Fi chip to full power, as this greatly improves reliability. However, you can manually change the power setting by going to Options -> Tools -> Wi-Fi -> Power control in WMWifiRouter. In our own experience there are only minor power improvements when setting the Wi-Fi chip to a lower power level, though it greatly affects reliability. Note that this option is not supported on all devices and this setting has to be re-configured every time you start Cellular to Wi-Fi sharing.