Heat is the deadliest type of extreme weather, and the human-caused climate crisis is making heat waves more severe and prolonged. Coupled with high humidity, conditions in some places are approaching the limits of human survivability — the point at which our bodies simply cannot adapt.
Here is what happens to your body in the heat:
Dehydration: Sweating is the body’s way to cool down – but it can also make you dehydrated because you may be losing fluids faster than you can replenish them. So don’t wait until you are thirsty to drink.
Heart: Your heart must work much harder to keep your body’s internal temperature stable, pushing blood quickly toward your skin, where it can release heat — this is the reason you may look flushed when you’re hot. And as sweat pours out, the loss of fluids reduces blood volume, meaning your heart is forced to pump even harder to maintain blood pressure.
Brain: Blood flow to your brain decreases in extreme heat as breathing speeds up and blood vessels constrict inside your neck and skull. This deprives your brain of the oxygen and glucose it needs, potentially affecting your cognitive abilities, worsening any mental health conditions and leading to risky or poor decision-making.
Heatstroke: When the body can’t use its usual tricks to cool down, its core temperature can reach catastrophic levels. A person with heatstroke can become disoriented and lose consciousness. Major organs start to shut down – the barriers that separate the gut from the rest of the intestines can become more porous, leaking deadly toxins into the bloodstream and the heart fails.
Read more about the effects of heat – and how to keep yourself safe – here.
