Burning up when traveling

How do I make sure my laptop stays asleep when the lid is shut?

Be careful what you leave open in the background. Chrome's minions ("helpers") seem to work even with the computer asleep. Some web sites even in Safari can stay active when you think the computer is not. Close everything before putting it in your backpack.

New computer are thankfully not like the old ones we graybeards had to use by candlelight . Old models took a long time to load, wake, do anything, so we tended to leave them in idle mode and accept some heating.

New computers start from cold faster than an old hard-drive system could launch one app. Leaving them off or with all apps closed is not longer a chore.

I have not experienced lid closure issues since my early silver-key Macbook Pro died. They suffered uneven lid closure due to lid bowing, a design defect, and I resorted to rubber bands just like my esteemed colleague D. I. Johnson suggests. For me the Unibody design solved the problem with better lid closure, but a band is insurance. However if software is the issue, the rubber band won't help.

However, check that you lid fully closes for one very good reason: a swelling battery can affect closing.

I can only suggest that you either strap the lid closed (Big rubber band? Velcro?) so that a partial opening doesn't trigger the laptop awake, or better, simply shut down the computer when you transport it in the bag.

I know of no way to "make sure my laptop stays asleep when the lid is shut".

Exactly which Mac, model and year is this Mac, and what macOS version is it running? Find that info by clicking the Apple menu () at the top-left of your screen and then select About This Mac. (Note- for privacy and security reasons, please never post your serial number.)

You're welcome.

This reads to me like you're trying to address this issue the right way. You're shutting down certain apps and features; ProPresenter and Bluetooth. Hopefully this continues to have positive impact.

I understand your distaste for the rubber band solution. It's so inelegant. But sometime things like this can make for some light, ice breaking conversation in group settings. 😃 Maybe you'd appreciate something a bit more retro, fun and interesting, like this old skool book strap:

All kidding aside, consider Allan Jones' suggestion of battery swelling and perhaps have the computer evaluated by a service provider.

Take care, friend. 🍀