This was me for most of my pregnancy. Where i work has no air con and so whenever i got overheated id get really lightheaded i remember one time i was serving a customer and it came on and my store manager was next to me i grabbed her arm and said im going to pass out. I don't know what happened but i just remember being in the staff room being fanned and handed a cup of water by the trainee manager.

Good thing your DP was there and no you wouldnt have done any damage. During my pregnancy i slipped over and fell hard on tiles, whacked my belly on a saucepan handle and on a pole on the bus and my bubba has turned out fine, more than fine!

Just make sure you don't over heat yourself.