The heat dome roasting millions of people across the Pacific Northwest, sending temperatures in usually temperate places to record-breaking triple digits, has already claimed hundreds of lives. And those are just the ones we can count so far.
Climate change has increased average temperatures by 1℃ Celsius over the past century, making heat waves like this one more frequent and intense than those from any other point in recorded history. A worldwide study published last month in Nature Climate Change found global warming responsible for 37 percent of heat-related deaths between 1991 and 2018. As temperatures tick ever higher, that figure may well rise.
The following is what happens if you’re one of the next people whom extreme heat kills, according to W. Lawrence Kenney, an expert at Penn State University.
First, your brain sends a series of messages to your sweat glands (腺体) telling them to ramp up sweat production. Then your heart starts beating faster to pump blood to the skin. That’s your body attempting to make your skin hotter than the air outside, in hopes of moving heat away from you. Sometimes that alone is enough to create problems for a weak or aging heart. If your body fails to cool you down, its internal temperature might start to climb. At that temperature, the tissues in the brain become affected. Before long, you might not know where you are or what time it is. You might collapse. You may lose consciousness. While you struggle to stay awake and avoid dizzying confusion, the excessive internal heat will likely trigger an inflammatory (发炎的) response. Left untreated, what follows is 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 susceptible (易受影响的) to it,” Kenney said. “That’s because we can’t ethically 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 body examinations of people who have died of heat stroke.”
9. What can we learn from Paragraph 2?
A.Rise in temperature is positively related to heat-related deaths. |
B.Heat waves are weaker and can be seen less frequently nowadays. |
C.Climate change has mainly triggered temperature decrease over the past century. |
D.Global warming contribute to most deaths related to heat between 1991 and 2018. |
10. What will happen to the person killed by extreme heat?
A.His heart will receive messages from the brain to pump blood. |
B.His body will turn cooler due to the quick response of the skin. |
C.He will have skin problems for weak or aging tissues. |
D.He will suffer from confusion, faint or even break down. |
11. Which of the following words can replace “ramp” in Paragraph 4?
A.Take. | B.Speed. | C.Turn. | D.Build. |
12. By quoting Kenney’s words, the writer wants to ________.
A.reveal how studies on animal models are carried out in the laboratory |
B.explain why humans cannot be used for experiments to study heat stroke |
C.illustrate many factors have influenced heat stroke and the deaths |
D.prove people know little about heat stroke and its contributing factor |