事件记录
面试官: 问题是, can you build up a tolerance to heat exhaustion or even getting heat stroke as the summer progresses.
大发娱乐请来了博士. 斯科特·扬奎斯特. He's an emergency room doctor at University of Utah Health Care. 问题是, can you build up that tolerance or is it just always the same.
Dr. 扬奎斯特: 简短的回答, 苏格兰人, 是肯定的, you can build up tolerance to heat exposure, and this has been shown for some time now, 实验, with human volunteer subjects, 你可以把它们, 通常, under conditions of exercise. So you put one group into an area where they're going to exercise under heat conditions, around 37 degrees Celsius or 98.华氏6度. You have them exercise for 20 minutes and then have a 10-minute cool-down period, 这样做6天, and they will tolerate passive heat exposure much better than somebody who exercises in the cold. 所以你可以发展这个.
当你暴露在高温下, a couple of things happen to try to cool your body and adjust to the heat stress. One of those is, you start to hyperventilate and that will reduce blood flow to your brain. So you start to lose the amount of blood going to your brain. That's why people can get altered mental status with heat stroke. 大发娱乐称之为中暑, not because they're actually having a stroke, 但是因为, 有点像中风, their brain is deprived of essential nutrients and oxygen. 这就发生了.
You also have a diversion of blood flow toward the skin, so you sweat and also your skin heats up so you can radiate heat from the body and try to lose heat that way. But that also reduces your circulating blood volume and so you get a drop in your blood pressure, 这可以是, in cases of severe heat stroke, that drop in blood pressure can lead to cardiovascular collapse.
And so you have a couple of compensatory mechanisms when you're exposed to heat, 在细胞水平上, there are these proteins called heat shock proteins. The heat shock proteins are produced in response to this, and give you this tolerance. So people who are exposed to exercise under conditions of heat build up this tolerance by producing these heat shock proteins. And what you find is that they hyperventilate less, there's increased blood flow to the brain compared to the group that hasn't developed tolerance, and so they're able to compensate much better. They also increase their plasma volume, so they hold onto water a little bit more, anticipating they're going to be sweating and things like that.
面试官: So at the beginning of the summer when I feel like, “哦,人, I'm just having a hard time handling the heat," versus the end of the summer, where I'm running and cycling, and it doesn't bother me at all, all those things are happening inside my body.
Dr. 扬奎斯特: 完全. That's why you feel better as the summer goes along in the same amount of heat.
面试官: And I would imagine that everybody's a little bit different. Some people probably have a natural higher tolerance, right?
Dr. 扬奎斯特: 是的,绝对. So if you are obese or overweight, it's going to make it harder for you to develop heat tolerance because you've got that extra layer of insulation.
面试官: If I'm interested in building up heat tolerance because I want to compete in some sort of an athletic event, is there a systematic way I should go about it, or is it just about getting out for longer and longer periods of time?
Dr. 扬奎斯特: There are several protocols you can look at online. So if you do a Google search, you'll find several proposed heat tolerance regimens that you can adopt. But 实验 it's usually just a small amount of exercise, about 20 minutes a day for 6 days straight, 在炎热中, being careful to hydrate yourself well and to stop if you're feeling dizzy or excessively tired, 这样就可以了.
面试官: 好吧. 好的，非常感谢. Indeed, you can build up a tolerance to heat exhaustion.
更新日期：2021年7月16日
originally published: August 6, 2015