Causes of the Heat
Leaving the cell phone on the charger all day long leads to them getting hot; every time a mobile phone is just it has a tendency to heat up. This is because there is current flowing into the device. Also, cell phones with many applications processing in the background have the tendency to get hot. Try clearing some of the remote applications and the heat level is likely to reduce. Sometimes the processing of a cell phone may lead to it emitting some heat. For example, using major applications like hotspots and playing games. The increased processing leads to heat production. A poor signal is also one of the leading causes of high mobile phone temperature while still charging.
Reducing the Probability of the Cell phone to Heating up
Sometimes the user of the mobile might tend to use a charger with a high current flow. Hence to reduce the hotness, it is always recommended that the mobile user charges the phone with a charger that has a small current capacity like 1amp. There will still be heat production but at a lesser percentage. Avoid leaving the phone while charging for a long time as the whole day or overnight to prevent the heat. Any phone is prone to heating up, but the user can reduce the degree of heat. This can also be by shutting down applications processing from the background if not essential.
Charging While Using
People have the tendency to use the cell phones still while connected to the charger. This means that the current is flowing from and to the mobile phone. Most likely it might lead to overheating and poor performance. It also limits the battery life, extra heat while charging could mean that the battery is already in poor conditions. This can be proven by the amount of time the battery power lasts. If the degree of heat is very high while charging, consider consulting an expert for assistance.