What's old is new again, but I welcome this.
I used to do this 15 years ago to keep listening to music from my laptop (one of the white chiclet ones) in my backpack, can't remember the name of the app I used then.
One caveat, your laptop cannot cool inside a backpack, it will overheat and shut down anyway. This happened to me several times.
It has a setting for thermal cutoff that you can set to something like 60º C. Sleeping will stop heavy work (like a build) before it leads to overheating.
that was true of intel but definitely not of arm macbooks.
Then why do they have fans?
Many ARM Macbooks do not have fans?
Many do. I would argue most do, although i don't have air vs. Pro sales numbers so I can't speak definitively there.
Even those that don't may rely on passive cooling strategies that are less effective in enclosed spaces.
Fans !== heat
My comment is only in response to https://news.ycombinator.com/item?id=48701824 , which is contending that ARM Macbooks have fans.
had a coworkers whose laptop keys melted into mush