A new article in the medical journal The Lancet has concluded much of the Northern Hemisphere will be too hot by 2085 to host the Summer Olympics. Researchers are projecting only eight cities in the hemisphere outside of Western Europe would be cool enough to host the Games. This includes just three cities in North America: Calgary, Vancouver and San Francisco. The list of cities where it could be too hot is staggering: Istanbul, Madrid, Rome, Paris, Budapest, Tokyo, New York, Chicago, Los Angeles—and the list goes on. Extreme high temperatures have already impacted the athletic world. In 2007, high heat forced the cancellation of the Chicago Marathon. At this year’s U.S. Olympic marathon trials in Los Angeles, 30 percent of the runners dropped out of the race due to the heat. For more, we speak with Kirk Smith, lead author of the article and professor of global environmental health at the University of California, Berkeley.