A tip from my rich girl friend who got it from her father's Japanese gardner. I take a large bowl of water with lots of ice cubes in it out and place it in the shade. Then wring out a small towel (the size beauty shops use is perfect) leaving quite a bit of moisture in it and place it around your neck (I actually LIKE it to drip down my front). Renew as the towel warms up. I have found this extends my ability to tolerate the heat by quite some time and it keeps me from sweating so much, therefore, less dehydration. Also, I know by the time all the ice has melted and the water in the bowel is warm it is TIME TO GO IN anyway. Enjoy.