An overview of heat injury and dehydration symptoms here:

Triathlon Forum
1

I presume we are not the only ones experienceing high temperatures. That being the case here is some information of the warning signs of heat injuries and dehydration.

I wager most of you guys are actually familiar with these, but this is something that sneaks up on you so here is a refresher:

http://www.rice.edu/~jenky/sports/dehydration.html

And directly from my favorite resource on heat injuries, “The Soldier’s Manual”

http://smct.armystudyguide.com/Skill_Level_1-AUG2003/081-831-1008.htm

**1. **Identify the type of heat injury.

**a. **Heat cramps symptoms.

**(1) **Muscle cramps of the arms, legs, or abdomen.

**(2) **Excessive sweating.

**(3) **Thirst.

**b. **Heat exhaustion symptoms. (The first five occur often. The others occur sometimes.)

**(1) **Profuse sweating with pale, moist, cool skin.

**(2) **Headache.

**(3) **Weakness.

**(4) **Dizziness.

**(5) **Loss of appetite.

**(6) **Heat cramps.

**(7) **Nausea, with or without vomiting.

**(8) **Urge to defecate.

**(9) **Chills (goose flesh).

**(10) **Rapid breathing

**(11) **Tingling of the hands and/or feet.

**(12) **Confusion.

**c. **Heatstroke symptoms.

**(1) **Flushed, hot, dry skin.

**(2) **Headache.

**(3) **Dizziness.

**(4) **Nausea.

**(5) **Confusion.

**(6) **Weakness.

**(7) **Loss of consciousness.

**(8) **Seizures.

**(9) **Weak and rapid pulse and breathing.

**2. **Provide the proper first aid for the heat injury.

**a. **Heat cramps.

**(1) **Move the casualty to a cool or shady area or improvise shade.

**(2) **Loosen the casualty’s clothing unless in a chemical environment.

**(3) **Have the casualty slowly drink at least one canteen of cool water.

**(4) **Seek medical aid if the cramps continue.

**b. **Heat exhaustion.

**(1) **Move the casualty to a cool or shady area or improvise shade.

**(2) **Loosen or remove the casualty’s clothing and boots unless in a chemical environment.

**(3) **Pour water on the casualty and fan him unless in a chemical environment.

**(4) **Have the casualty slowly drink at least one canteen of cool water.

**(5) **Elevate the casualty’s legs.

**(6) **Monitor the casualty until the symptoms are gone or medical aid arrives.

Note. If possible, the casualty should not participate in strenuous activity for the rest of the day.

**c. **Heatstroke.

WARNING

Heatstroke is a medical emergency that may result in death if treatment is delayed. Start cooling measures immediately and continue while waiting for transportation and during evacuation

**(1) **Move the casualty to a cool or shady area or improvise shade.

**(2) **Loosen or remove the casualty’s clothing unless in a chemical environment.

**(3) **Spray or pour water on the casualty and fan him unless in a chemical environment.

**(4) **Massage the casualty’s arms and legs unless in a chemical environment.

**(5) **Elevate the casualty’s legs.

**(6) **If the casualty is conscious, have him slowly drink at least one canteen of cool water.

Note. Watch the casualty closely for life-threatening conditions, check for other injuries, and seek medical aid.

2

I thought people may be more interested in this. Hmm.

3

Thanks for that, Tom. As it happens, I had a version of this happen to me this past Sunday during a 3-hour ride at 90 degrees F and high humidity. It was my first ride of the season at over about 75.

My troubles came when I turned back north after an hour and half and had a tailwind rather than a headwind. Climbing hills, the apparent wind was just about zip. I started to feel that characteristic prickly skin along with mild chills and nausea. I’d been there before and knew to slow down. I wasn’t thinking clearly enough, however, to figure out all of what was going on.

I made it home but wasn’t in good shape. I felt really whoozy on my feet and also had some visual disturbance. I think if I hadn’t sat down, I would have fallen down. I drank some cold water and more sports drink and gradually began to feel better.

It wasn’t until I was in the shower that I noticed how bloated I was. During lunch the bloating began to ease and it dawned on me what had happened.

My habit on a 3-hour ride is to drink water for the first hour and then add sports drink at about 150 kcal/hour. I now think gastric emptying stopped somewhere between an hour and an hour and half in. Besides the heat problem, I bonked. I can go two hours without adding calories but not three.

That’s what makes this sport so great. After a decade of triathlons and 25 years of cycling, I can still find new ways to do myself in.

David

4

I noticed a very interesting statement in the Rice link…

“Choice of Fluid”.

"A full discussion of all the available beverages and the science behind their content is beyond the scope of this article. For races lasting less than 1 hour, water alone is adequate. For longer races, there are many commercially available sports drinks. The most important features are taste, carbohydrate and sodium content.

Taste is important, because if you don’t like it you won’t drink it. Don’t try a new sports drink on race day. Carbohydrate content in the range of 4 - 8% is best for endurance races. Levels above 10% are poorly absorbed and can cause diarrhea. Most sports drinks have a sodium content in the range of 10 - 20 mmol/liter (Gatorade is 23 mmol/liter = 1.3 grams of salt per liter). Higher levels are better for salt replacement, but tend to be less palatable. There doesn’t appear to be any advantage gained from adding other electrolytes (e.g… potassium, magnesium) since the diet is usually adequate to replace these."

This certainly makes it sound like gatorade is adequate for hydration and electroyte needs. There are certainly lots of expensive drinks with all kinds of stuff in them. What is the advantage of over gatorade if you remove personal taste preferences?

5

Well, for my money, a lot of the copy written about sports drinks amounts to marketing. As long as the solution is appropriate for you - that is, the percentage of carbohydrate in the mix and the fact that it is a complex type carbohydrate as opposed to a simple sugar- those items are significant.

Also, the sodium/electrolyte combination is worth looking at. Higher may or may not be better. That is contingent on environmental issues and your individual ability to tolerate a process the solution.

And therein lies the big factor: Osmoality (sp?), or the absorption rate. Generally, a higher carbohydrate solution means less absorption, especially as the temperature climbs.

Another product I really like in the heat is E-Gel, an electrolyte laden, complex carbohydrate energy gel that not only packs a carbohydrate whallop but has over four times the electrolytes of other gels, making something like Endurolytes unnecesary. Also, as for absorption rates, E-Gel is “tunable” for temperature and concentration. If you drink 12 ounces of water with a 1.9 oz. gel packet the concentration (and attendant absorption rate) is less than if you were to drink 20 ounces of water with the same gel pack.

I think E-Gel is particularly well suited for warm temperatures. I think it saved my race at Ironman New Zealand in 2004.