Shower sexy time....

Ti
Ever since I've been pregnant
And we have had sex in the shower, after we are 'done' I feel like blacking out and I have to sit in the tub. He will turn in the cold water and spray me with it and it shocks me back to normal. Why is this happening? Too much heat? Steam? Movement? I never have the water spraying on me during, the vents on and the door is open. It's embarrassing.