Severe heatstroke can make your gut leak toxins

During a sprint or heavy labor, your muscles transform into a biological furnace, generating over 1,000 watts of heat—roughly the same output as a portable space heater. To survive, your heart pumps blood furiously to the skin while sweat glands work to shed this energy into the air. But if the humidity is too high or the air too hot, this cooling system stalls. Once your core temperature crosses the threshold of 40 degrees Celsius, the very proteins that hold your body together begin to lose their shape, and the delicate membranes protecting your cells start to liquefy.