A heat wave roasted millions of people across the Pacific Northwest, claiming hundreds of lives. Climate change has made heat waves like this one more frequent and intense than those from any other point in recorded history. A study published in the journal Nature Climate Change found global warming responsible for 37 % of heat-related deaths between 1991 and 2018.
The following is what happens if you're one of the next people whom extreme heat kills, according to W. Lawrence Kenney, an expert from Penn State University. First, your brain sends messages to encourage sweat production. Then your heart starts beating faster to pump blood to the skin while blood flow is also directed away from your liver, kidneys, and gut. That's your body attempting to make your skin hotter than the air outside, in hopes of creating a convection (对流) phenomenon that moves heat away from you.
If heat stroke (中暑) occurs, your body might get so hot and redirect so much oxygen-rich blood to the skin that it fails those vital internal organs. Surviving the organ failure that follows might require an emergency transplant. If your body fails to cool you down, its internal temperature might start to climb from a normal level of about 98 degrees Fahrenheit to somewhere closer to 104 degrees. At that temperature, the brain becomes affected and you may feel it start as a headache. Before long, you might not know where you are or what time it is. Left untreated, what follows is a series of organ failure that leads to all but certain death. And that's just part of what we know about how extreme heat kills you.
"It's important for people to understand that there's still a lot we don't know about heat stroke and who's most likely to be harmed," Kenney said. "That's because we can't study it in humans in the laboratory. A lot of what we know comes from studies on animal models, like mice and rats, or from postmortem examinations (尸检) of people who have died of heat stroke."
