Cardiac arrest during a marathon is certainly the stuff of runners' nightmares, but if you're going to let anything cause you anxiety during your next race, it should be heatstroke. Heart-related deaths tend to get a lot of attention, but a new study says that heatstroke is a much more common danger for runners.
Cardiologists from Tel Aviv, Israel, found that for every incident of cardiac arrest either threatening or taking a runner's life at a long-distance race, there were about 10 incidents of heatstroke doing the same. Heatstroke is the most dangerous form of heat illness, entailing fever above 104 degrees and symptoms like losing consciousness. Yes, Tel Aviv is a particularly hot place, but heat is still responsible for about 700 deaths each year—and you might not even realize when it's putting your life in danger. You could feel dizziness or nausea, for example, but not much else out of the ordinary.
That said, heatstroke is preventable, and it's not necessarily a death sentence. Use common sense: Hydrate and don't push yourself too hard if you're feeling overheated. As several physicians pointed out, immersion in a tub of cold water for six or seven minutes can effectively prevent organ damage or death for most who do fall victim to heatstroke. So don't sweat it too much.