Why is my computer not turnin on?

I was using my computer on my bed and then i left for about 2 hours. I think i left it on charge there and the bottom of my computer was really hot, so I think it overheated but I've looked in every single article on google and can't find a good reason it won't turn on. I also see that the low battery signal is on, but I've been charging it for a whole day. Help me find a solution.