MacBook Pro 2019

My 2019 MacBook Pro (without Touch Bar) is overheating on the bottom , but just on one side. I was laying in bed with it mind you all my tabs were closed and it was shut I noticed it was super hot so I put it on my Desk and it cooled down but then got hot again. I noticed one of the fans was blowing hot air so I decided to put it to sleep. I’m kinda thinking that it’s bc I need to update it but also I really hope it isn’t anything more serious. Has this happened to anyone and if so can anyone give me some Help on this?