Your PC will continuously run and will overheat in your bag. If you just close the lid and put your laptop in a bag, it will never go in sleep mode and may cause severe problems due to poor circulation or blocking of vents. But, you need to be more careful, especially when you travel. That means when you will close the laptop’s lid, it will not go into sleep mode. It is possible on Windows 10 to change its behavior.
When you close the lid, your PC will go into sleep mode, which you may not want. But, if you want to connect your computer to an external monitor, you may face problems. By default, when you close the lid of a Windows 10 laptop, your machine goes in low power sleep mode.