You guys are great - thanks for the responses. We are most often dealing with high humidity (being on the coast), so 80 degrees can feel much warmer. I think I will use 75 degrees as Kipawa's upper range. Also, the heat yesterday came on with a bang - no buildup to it. It just happened. So there was no time for man or beast to get used to it. Anne, your comment about "a dog will keep going with you till they collapse from heatstroke" is exactly what would happen to Kipawa. He just loves his outdoors and running so much. Once outside, he does not have a "slow" setting if he is off leash.