So I live in Phoenix, where it was 113 degrees today. It was 107 at 7:30 PM when I just played Tennis for 2.5 hours. I had wetted one of these and threw it in the freezer for a couple of hours. Then when I started playing, I poured a little cold water from a bottle on it, wrang it out and through it around my neck. Thing was ice cold and felt really good. About an hour and half later it was still wet, but not cold, so I poured a little more cold water on it and instant relief. I have been playing tennis all summer in the 105+ degree heat and had several instances of getting a bit light headed even after an hour at times. Not tonight. So highly recommend.