Is it normal to feel like this?

So last night I took a bath. When I got out, I felt really dizzy and I just sat on the toilet for probably 5 minutes. I got up, put some pajamas on and I was still really dizzy and I felt tired. I went to my room and layed on my bed. I could feel my heart pounding really hard and I couldn't open my eyes. I ended up falling asleep and sleeping for 5 hours. I feel fine now. What happened? The water was hot, by the way. My back was hurting so I thought it would help.