Over heating.....

Luckily it's fall here but we just had unusual hot weather this weekend (80's). I was outside in the sun for maybe 2 hours and have never had this happen before. 
I started to feel hot, very hot so I sat down. My vision started to get black and fuzzy fast. So I told my fiance I need to go inside. As we walked I could not see. His dad held one side of me while him on  the other and got me to shade. They have me water and ice to put on my head as I recovered for a while. It was so scary. I was afraid of falling and hurting the baby or myself. I've just never had that happen before, wow! Anyone else bothered by the heat?