This was just sent around by someone in the Safety department at one of our mills, and I thought it was good enough to post here. It got my attention partly because my sister-in-law did get a case of heat exhaustion over the week-end. Of course almost all of you probably deal with heat more than we do here in Maine, but we here are not used to this 90 degree humid heat. In any case, it's a good review if nothing else.

Hmmm, it would seem as if I have suffered from heat exhaustion on a few occasions. At least, very mild exhaustion...

What kind of temperatures bring about these conditions? It's 85-92 F around here and I'm wondering what sort of risks I'm taking.

Generally, it is not the environmental conditions but the lack of preparedness for the conditions. A few regulars in this forum commute many miles in very hot, dry climates, and none of us, AFAIR, have reported heat cramps, much less exhaustion. And yet, we see reports in the summer of people being evac'ed from the city parks because of heat exhausation while they were walking in the same conditions.

The difference is preparedness. Drinking water before, during and after will allow you to handle many conditions, even humid heat. How much should you drink? My own rule of thumb is enough to keep my pee clear. This generally translates into two liters at work, a bottle each way to and from work, and several glasses of water at home in the evening. And, yes, I pee a lot.

Salt tablets! and lots of water. I try to nip it in the bud before I'm laying in the shade of some tree, puking, with a killer headache and the inability to stand fully upright. No fun. A one hour bike ride or a commute is much less dangerous than a full day of touring or a century.

Last time I had it was a year ago skiing on a 12,000 foot volcano on the Fourth of July, man was it hot out! By the time you realize you've headed for a bad way, if you keep exerting yourself without taking some remedies like rest, shade, etc. you will be absolutely miserable in just a few more hours.

This is one of my favorite topics--thanks to the OP!

I lived in sub-Saharan Africa for three years, and while there, I learned how to deal with heat quite well. Daily temperatures were 90-110 degrees F, year-round, and I had no A/C or electricity. I eventually learned to adjust quite well. One thing that most people in the northern hemispheres don't realize or understand is that human beings are uniquely evolved to deal with heat. In fact, that's one of the characteristics which distinguishes our species from almost all other mammals (camels being a notable exception). We're made to be active in the heat!

Oddly enough, because of our ignorance, doctors and public health professionals are always having to put out 'warnings' like those above, which often serve to inform but also intimidate people into avoiding the heat. Avoidance is not the most effective strategy, and it ultimately leads to a diminished tolerance for people, which is contrary to the natural structure of our bodies.

Our unique adaptation? Sweating, which allows the body to regulate not just our brain
temperature, but our entire body's temperature. When I lived in Africa, I usually consumed 8-10 liters of water a day. I would sweat constantly and profusely. The more a person spends time in hot temperatures and being active in hot temps, the more the person will sweat, the more water they will take in, the more efficient their body will become at maintaining temps. The main point to understand is that keeping steady and active and functioning in heat requires acclimating to the heat, and this is only done by staying hydrated. Drink water. Drink more water. And when you're done, drink some more water. As long as you are sweating, you are in good shape. One thing I learned while in Africa was that if I was dehydrated, I would stop sweating: as soon as I drank some more water--almost instantaneously--I'd begin to sweat profusely. I suffered from Heat Exhaustion a few times, and usually, merely re-hydrating would not help. I had to actually nap afterwards, in order to get rid of my splitting headache and general sense of disorientation. If you suffer any symptoms, don't push yourself. Find some shade, drink water and let your body relax.

Salt and sugar in your water also helps the body to absorb water. If you're feeling a bit dehydrated in the heat, you can always throw some of that into your water, or eat some fruit and salty snacks. If you're in the heat a lot and sweating a lot, you're tolerance and cravings for salt will go up, which is natural and healthy: it means that your body is adjusting and requiring more salt for water absorption.

Pro atheletes always train for dealing with heat by subjecting themselves to extreme heat and being active in it. This strategy increases the body's sweating and therefore cooling efficiency.

The main point here is that to deal with the heat, you shouldn't avoid it, you should be active in it. Don't be risky, and don't overdo it, but don't be afraid of it, either. I find now that when I spend a day in hot temps, and then go into an A/Ced environment, I actually come out and have a really hard time re-adjusting. I've been out riding around here in NY in our 90+ temps on a daily basis, and doing fine. My friends, meanwhile, have been turning on their a/cs and hiding from the heat, and they're having a doozy of a time adjusting to summer. I also find that the heat helps my skin and joints, and I'm definitely not so achey or sore when I exercise in the heat.

Also, as most are aware, humidity increases the effects of heat. Even though you might not feel the need for it, you should drink plenty of fluids on mildly hot days that are humid. You still need to sweat in that environment.

I'm sure that sweating causes a lot of other ancillary problems in the way of commuting, but don't let those things change your behavior in the heat. If you are going to do it, you will have to sweat. Deal with your wet clothes, not a case of sunstroke.

One other thing: if you have any kind of serious/chronic health condition, these points do NOT necessarily apply. I know that people with MS as well as some overweight people, and probably others, can be in real danger in extreme temperatures. I would suggest consulting your doctor beforehand.

But just because you feel uncomfortable, does not mean it's bad for you. You WILL adjust. If you feel that you can, try a week without a/c and see how you deal with temps at the end of it. Try using natural air circulation in your home; sleep with fans on and the windows open (a shower before bed usually cools you off enough to sleep); adjust your attitude to accept the ambient temperature as a given and a/c as unecessary. You may find yourself looking at the thermometer and thinking, "Wow, it really doesn't feel like it's 95 degrees right now!" You'll also find that you're getting into great shape and actually enjoying the summer that you're environment is giving you.

Enjoy it. Over half the world's population lives in hot, tropical climates, and they get along quite well in it!

Yeah, if you're physically fit, then all you need is lots and lots of water and electrolyte replacement. Then, you can handle almost any heat the earth's surface can throw at you*.


*Close proximity to liquid magma and other geothermal events not included.

Yeah but try not to die from too much water.

Right you are. Thanks for pointing that out. I read that article too. The worry there is people who just aren't working that hard drinking too much--usually because they're worried about being dehydrated. And they're not usually in extreme heat.

I don't think this is a huge worry unless you're out drinking and drinking and drinking but not really being active enough. These are slower (many first-time) marathoners who probably aren't moving very quickly or that hard and drinking a LOT of water. A lot of people who do marathons now do the 1 mile run/1 mile walk. That's just not that active. It's interesting to point out that the reason these people began suffering from this problem is that they were carefully heeding the mantra of professionals, but not fully aware of the reasons for doing what they were told to do. Hydration is important for maintaining your body temp., and if you don't need to do that, you don't necessarily need to stay so hydrated.

The people mentioned in the article did not necessarily suffer these problems in extreme heat. If you're in hot temps., it's veeeeery difficult to overhydrate--your body just really needs to be sweating constantly.

But thanks for the proviso, oboeguy!

That pretty much the norm here in Texas untill late September. As other have said, drink lots and lots of water. Also, just as important is taking it easier during the hottest time of the day if you are not use to the heat. Pretending to be Lance Armstrong when its 98 degrees with 80 percent humidity is just asking for trouble.

I think not being overweight plays a big factor in heat tolerance too. I found as I lost weight, I could handle heat fair easier than when I was packing an extra 20 lbs. I suppose its due to having less insulation to trap the heat.

This kid was probably in better shape than most of you. The Lesson here is about proper hydration and balance.
While "water intoxication is an issue, Severe dehydration is much more common occurence

Dehydration at root of Dad Vail rower's death

By Ray Parrillo and Susan FitzGerald

Inquirer Staff Writers


Scott Laio, the 20-year-old Boston College rower who collapsed after his boat crossed the finish line at the Dad Vail Regatta on May 14, died from a fluid and electrolyte imbalance and heat stress, the Philadelphia Medical Examiner's Office said yesterday.

Dehydration can send body chemicals such as potassium, sodium and chloride - they are called electrolytes - into a state of imbalance, potentially causing the function of body organs, including the heart, to be disrupted.

"If the electrolytes are out of whack, then the most likely problem would be an irregular heartbeat," said Edward Gorrie, who frequently treats athletes as director of student health at St. Joseph's University.

Gene Hong, chief of the Division of Sports Medicine at Drexel University, said heat stress alone can result in death, even if an athlete is only slightly dehydrated.

"Everybody's tolerance for heat is different," he said. "Some athletes tolerate high temperatures better than others... . Heat stress, fluid imbalance and electrolyte imbalance are all a little different, but they are interrelated."

Alfred Bove, head of cardiology at Temple University Hospital, said athletes routinely lose a lot of fluid during exercise.

"It's common for athletes to have a moderate electrolyte imbalance" after a period of exertion, he said, though the condition is usually not a problem for healthy, young people.

Bove, who was speaking in general and not about the Laio case, said an underlying condition, such as an inherited heart-rhythm disorder, could make a person especially vulnerable to an electrolyte imbalance.

On a sunny day with the temperature about 80 degrees, an emergency medical team that was on site attempted to revive Laio on a dock alongside the Schuylkill. Laio, who was in the bow of the boat that won the varsity lightweight-eight gold medal, was taken by ambulance to Hahnemann University Hospital, where he was pronounced dead at 4:52 p.m., an hour after he collapsed.

As a lightweight, Laio, who was listed at 6-foot-2 and 166 pounds on the crew team's Web site, had to meet weight requirements for a boat on which the rowers must average 155 pounds. An athletic trainer for a local college who requested anonymity said he and some of his colleagues suspected Laio may not have properly hydrated in an effort to make the weight.

"I don't know the facts of the case, so I don't want to speculate, but he was a guy who had to be conscious of his weight, and he may not have been properly losing weight," he said.

Boston College officials declined to comment on the findings.

"Scott Laio died a tragic death, and this is a very sensitive time for his family, coaches and teammates," athletic director Gene DeFilippo told the Associated Press. "Out of respect for them, we have no further comment on this situation. The Laios remain in our thoughts and prayers."

At the Dad Vail, the nation's largest collegiate rowing event, weigh-ins for lightweights are done the morning of the race, according to Robert H. Morro, the regatta's secretary. The weigh-ins, he said, begin at 6.

"We do that so they can have plenty of time to eat and drink before the race," Morro said yesterday.

Timothy Hosea, USRowing national team physician and chairman of the USRowing Sports Medicine and Research Committee, said recently that careful measures are taken to make certain that rowers on the national team do not engage in rapid weight loss.

"I've never seen anybody sick because of weight loss in any regatta I've participated in," Hosea said. "In general, the mind-set of a rower doesn't lend himself to that... . Rowing is simply too hard a sport for the rowers to be effective after rapid weight loss."

But James Rogers, a certified athletic trainer and program director for Temple Sports Medicine Centers, said dehydration can be a problem for athletes who have to make weight to compete. For instance, he said, athletes will do intense workouts to sweat off water weight and cut back on drinking liquids before they are weighed in.

"Employing dehydration techniques... makes them at special risk," Rogers said.

Laio, from Pittsford, N.Y., was an experienced rower who had competed for three years on Boston College's crew.

The American College of Sports Medicine recommends that athletes drink plenty of fluids 24 hours before an event, consume at least 17 ounces of fluids two hours prior to an event, and continue drinking at regular intervals to replace fluids lost through sweat.

Typically, athletes can lose 5 to 10 liters of fluid during intense exercise, which can lead to dehydration, the medical examiner's office said.

Mike Cipollone, an assistant coach at Monsignor Bonner High and the father of Pete Cipollone, the coxswain on the 2004 U.S. Olympic heavyweight eight that won the gold medal, said Laio's death served as a tragic reminder.

"You can't overestimate proper hydration on a continual basis," he said.
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I'd never heard of this phenomenon until a month or two ago when the NY Times had an article on it. As someone who's gotten pretty messed-up from dehydration, I was really surprised to see that things could go the other way, so to speak. Anyhow, letting y'all know.

Regarding dehydrating to make weight, I remember wrestlers in school doing that -- they run laps by the indoor pool (hot, humid) to make weight. For wrestling it's not as big a deal if you're a bit dehydrated as it is for rowing or cycling (or running, etc), but I still think it's stupid and dangerous.

Anybody remember the 2003 TdF? Lance got blown-away in the first time trial because he was dehydrated. He said it had accumulated over a couple of days, IIRC.

The article was sent around in response to predictions of temps in the mid- to high-90s F and high humidity. I know many parts of the country have higher temperatures more constant, but some of them are also drier.

It was interesting for me to read. I've been finding the last couple of years that I can get a headache pretty easily just being out in the sun without a hat, even if the temps are very moderate. Maybe my heat tolerance is be falling...

Severe water intoxication cases usually occur under the effects of a few certain drugs. Aside from that it's pretty hard to pull off, and even then is usually pretty minor unless the person was deliberatly cramming water for some ungodly reason.

Thing is the human body will find ways to flush that excess water (think "the runs"). What these "certain drugs" do I forgot, but it basically defeated the body's methods for dealing with too much water, allowing for extremely rapid absorption of water....very bad.

Pretty much Peripatetic summed it up greatly. If you are not sweating, stop and drink some water (preferably some sports drink as well) as you are already showing signs of dehydration.