I recently upgraded my MacBook Pro to Mojave 10.14 mainly as Outlook had stopped working properly, and I needed to upgrade the Mac OS X so that I could install the latest version. Generally no real issues except one.
In the past when I shut the lid of the MacBook Pro it would sleep and when I opened the lid it would wake.
However on a couple of occasions now I have noticed as I reached into my rucksack that my MacBook was hot, really hot.
What appears to be happening is that the MacBook is not going to sleep when the lid is shut. It keeps “working” and as it shut (and in a bag) it just gets warmer and warmer. The fans kick in, but even then it can’t cool down properly (with the lid shut and in a bag).
Of course I don’t think this can be good for it, so will need to check if the MacBook is in fact asleep or shut it down properly before putting it in the bag.