Originally posted by Joe Gardner
Jon, never drink cold water or ice when hot and dehydrated! Just a few years ago a lady cyclist lost her water bottle on the slick rock trail in Moab UT, she was totally dehydrated and couldn't bike, or walk to the trail head. After a few hours in the 100+ degree heat some guys in a jeep found her on the trail, they offered her water but she refused, and just wanted her water bottle back. Long story short, the jeep guys told her that she needed to drink water, she gave in and drank some ice cold water that the guys had in there jeep. within minutes she went into shock and almost died! If she would have drank her warm water, she would have been just fine, so be careful 
That's heat stroke, Joe, a different animal: your brain is cooking like egg whites. Drink before you get thirsty, and ice cold water in the tummy really keeps your temp down, avoiding scenarios like this one.
All I ever read about heat stroke ("a few hours in the 100+ degree heat") is that you'd better cool the victim down with wet towel, shade, water, etc., or they will die. But you may be right about forcing ice cold water down a heat stroke victims throat!
See:
www.gorp.com/gorp/publishers/ics/hea_medb.htm
Joe, after reading this link, I have to disagree completely with your post. This woman needed immediate first aid and medical attention. Her warm water bottle would have done very little for her at this point. I'd have to side with the guys in the jeep, they probably saved her life.
NOTE: UPDATE...DUE TO THE SENSITIVITY OF SOME INDIVIDUALS TO ICE COLD DRINKS, PLEASE CONSULT A
MEDICAL PROFESSIONAL BEFORE DRINKING THEM AS DESCRIBED IN THIS POST. SOME PEOPLE FACE A SERIOUS RISK FROM DOING SO, ESPECIALLY ASTHMATICS AND PEOPLE WITH ATRIAL FIBRILLATION (AF). REPEAT, THESE PEOPLE ARE SERIOUSLY AT RISK.