MacBook Pro M1 is overheating after closing the lid and putting it in a sleeve

Before putting the computer in the sleeve, make sure it has gone to sleep. It's possible that sleep is being interrupted by some process. You can click Apple menu  > Sleep and wait a moment until the screen darkens before you put the laptop in the sleeve.

Alternatively you can shut down the computer before you transport it. The M series Macs are pretty quick to boot when they do.

Neither of these is as convenient as simply closing the lid and slipping it into the sleeve, I know, but that doesn't seem to be working for you.

As to the cause, it's possible that a hardware fault is the issue, in particular perhaps a bad lid angle sensor. Hardware problems can be diagnosed at Apple or an Apple Authorized Service Provider.

It's also possible that you have some software that is interfering with the sleep process.

Do you have any anti-virus, cleaning, optimizing, security or VPN apps installed? These are often problematic in many ways. These are also unneeded in macOS.

You can try rebooting the Mac in safe mode and see what happens when you sleep it with the lid from that mode. If it works as it should, then that could be a clue. How to use safe mode on your Mac - Apple Support 

mr.nattapong wrote:

Thank you very much for the advice. i will try and update.

You're welcome.

And please do. 👍🏽