I am 22, male, with a normal BMI, a year ago i experienced a sudden feeling of extreme heat, sweating, followed by a small blackout, just after smoking 3 cigarettes in a row. Got conscious on pouring cool water on my head. Similar incidents happened 2 more times after that, once while smoking hookah, and recently while trying weed, though I avoided the blackout by pouring cold water beforehand. l'm an occasional smoker. All the three cases happened in summer, while I was empty stomach.