内容摘要：The foundation would still maintain control over food distribution, but there would be a period of overlap with aid groups, the letter said.

The foundation would still maintain control over food distribution, but there would be a period of overlap with aid groups, the letter said.

“That sets off a cascade of effects,” Jay said. “Clotting around the body and multiple organ failure and, ultimately, death.”But the bigger killer in heat is the strain on the heart, especially for people who have cardiovascular disease, Jay said.

It again starts with blood rushing to the skin to help shed core heat. That causes blood pressure to drop. The heart responds by trying to pump more blood to keep you from passing out.“You’re asking the heart to do a lot more work than it usually has to do,” Jay said. For someone with a heart condition “it’s like running for a bus with dodgy (hamstring). Something’s going to give.”The third main way is dangerous dehydration. As people sweat, they lose liquids to a point that can severely stress kidneys, Jay said.

Many people may not realize their danger, Houston’s Gandhi said.Dehydration can progress into shock, causing organs to shut down from lack of blood, oxygen and nutrients, leading to seizures and death, said Dr. Renee Salas, a Harvard University professor of public health and an emergency room physician at Massachusetts General Hospital.

“Dehydration can be very dangerous and even deadly for everyone if it gets bad enough — but it is especially dangerous for those with medical conditions and on certain medications,” Salas said.

Dehydration also reduces blood flow and magnifies cardiac problems, Jay said.The best way: Cold water immersion. Basically, “you drop them in a water bucket,” Salas said.

But those aren’t always around. So emergency rooms pump patients with cool fluids intravenously, spray them with misters, put ice packs in armpits and groins and place them on a chilling mat with cold water running inside it.Sometimes it doesn’t work.

“We call it the silent killer because it’s not this kind of visually dramatic event,” Jay said. “It’s insidious. It’s hidden.”This story has corrected to “humidity,” rather than “temperature” in a mention of how people’s function is affected by humidity.