Two times in the past couple of months I had strange episodes while exposed to heat. Both times, after smoking a cigarette and standing in the sun, I started to feel weak and overheated. The first time I sat in the shade and then suddenly I realized my vision was black and it felt like i was being shook by my boyfriend, who kept saying my name. it turns out i was convulsing and he was trying to hold me still. I came to all of a sudden and after some rest and water i was fine. the second time took place walking from my car to a building in a sunny parking lot. again, i had just smoked a cigarette, and while walking the 300 ft to the building i started to feel dizzy, weak, and overheated. when i took a seat inside the air conditioned building i could barely hold myself up and my hearing got completely screwed up-- i could hear only my boyfriend very faintly, and i was in a loud, crowded casino! i kept my eyes closed and after a minute or so my mind cleared a little and i realized i had broken out into a cold sweat. i had to sit there for a while longer before i felt alright to make the trek back to the car. I m 18 and in fairly good health. I ve only passed out from (grossly enough) vomiting so hard that I didn t have time to breathe (BAD food poisoning ). the only bad habits i have are smoking and a tendency not to eat much in the mornings. so were my experiences heat stroke , or possibly something else ? I also experienced some weird muscle pains in my legs and my abdomen after coming to from these weird episodes. some research has informed me about heat cramps, and i think these may fit the bill.