Exertional heat stroke is one of the few emergencies in which bystanders can truly save a life, and you don’t need to be a doctor to do it. It can strike even in mild temperatures, even trained runners, even a few meters from the finish line. In 50 minutes, with Luca Carenzo, emergency and intensive care physician and medical director of the Milano Marathon and Roma Marathon, we learn to recognize the signs, debunk the myths, and do the only thing that really matters: cool down immediately. A practical workshop for runners, coaches, run clubs, and race organizers.