Phones heat up during gaming due to increased CPU and GPU usage, which generates more heat. Intensive graphics and processing tasks demand more power, causing the device to heat up up. Additionally, prolonged gaming can strain the battery.
Please check if you have enabled the performance mode. When the performance mode is active, it ensures maximum output while gaming, however, the high load can generate significant heat, which makes you feel uncomfortable if it exceeds body temperature. This is normal. All Xiaomi products are thoroughly inspected before leaving the factory to ensure safety under various conditions. If you find the temperature too high, consider disabling game acceleration and switching to balanced mode while using the phone in cooler environments for a better use experience.