Alright, I need help. so I just got back from outside being extremely cold and took a very hot…

Alright, I need help. so I just got back from outside being extremely cold and took a very hot shower right when I got inside. But as I was standing there after about 10 minutes, I got very lightheaded to where the whole room was spinning. Then, I couldn't even walk because I was so dizzy then I fell. Tried to get up and head was pounding and then fell again. I'm 12 weeks 3 days pregnant. This has never happened Before. Need help!!!!! This all happened in the bathroom before my clothes were even on