See, if we talk about heating, then we have to say that every electronic device or machine is hot. For example, your car , computer, etc., everything is not prevented from getting hot. Water is poured to keep the car cool , the fan is used to keep the computer cool and it also has a heat shield inside . So you can actually say that it is hot because the smartphone is an electronic device. Processor: The first thing that causes the smartphone to get hot is the processor. The processor is similar to the main part of your phone. That does everything your phone does. Whether you use the phone or not, the processor is always running and working. And this processor is made of semiconductor material. And inside it are a lot of tiny electrons. When the processor does its work, these electrons run from one place to another (in simple language). And during this race, the electrons collide with each other and produce heat. This means that the more work your processor does, the more heat it produces. If you work less , say just talking on the phone , or listening to music, your phone will be less hot. But if you think you are playing a game and downloading a file from the Internet at the same time , but normally your phone's processor has to do more work and as a result your smartphone will be hotter. Nowadays car smartphones are getting thinner day by day. Now the heat generated by the processor cannot escape because your phone is thin. And notice that your phone's processor sticks to the phone body , causing you to feel very hot and very hot. Excessive load: I have already said that excessive load will make your phone faster and hotter. Normal tasks such as talking on the phone , sending SMS or listening to music will make your phone less hot. But when you do a lot of work at once or do some big work, your phone will be subjected to excessive load and the smartphone will be extremely hot. Battery: Smartphones are getting thinner day by day. But there is not much improvement in battery technology. Then the phone is very thin so the devices do not have too much distance from each other. When the battery is charged or discharged, it is more or less hot. And the devices do not have too much distance from each other so the heat of this battery spreads everywhere and your smartphone gets extremely hot. Ambient Temperature: Smartphones are extremely hot , which is another big reason but ambient temperature can be. Normally, the temperature in Bangladesh reaches 35-45 degrees Celsius in summer. In this environment, even if you are sitting at home, the temperature around you is around 35-36 degrees Celsius. And if you use a smartphone in this temperature, it will heat up more quickly.