Throughout the US and around the world, extreme heat is on the rise. It's a trend that many of us have perceived even in our own lifetimes. We talk about how heat waves have gotten hotter, less bearable. Kristina Dahl, PhD Senior Climate Scientist, Union of Concerned Scientists, explains that extreme heat already presents serious dangers to our health and livelihoods. She looks at data and talks about the future. Series: "Mini Medical School for the Public" [Health and Medicine] [Science] [Show ID: 35980]