 two summers ago, was a perfect example of how dangerous heat is, even to people who are youngish, who are in good shape, who think that they understand this. This family of 40, a man in his early 40s, a woman in her late 30s, and their one and a half year old child and their dog went for a hike on a warm summer day. They knew it was going to be hot. They started out early in the morning.