Why is my charging light turning on when I fold them?

So I got my headphones about a month ago.Since then I had no problems.Recently,when I folded my headphones the red charging light turned on.I made sure the headphones had full charge in them.A few days ago,while I was using them,the headphones got extremely hot.I checked the charge and it suddenly went to 0% even though they were fully charged.Some kind of malfunction maybe?Help!