Heat injury can easily and quickly turn you from a hard-working prepper into somebody who is entirely incapacitated or dead. It’s serious stuff, so let’s take a look at what it is and what it looks like. Salty and I talk about it in this podcast:
Heat injury can sneak up on you
It was a firm belief of my mother that “No one ever drowned in sweat.” Just in case, she taught us to swim though. And she taught us the basics of today’s topics…I admit I’ve supplemented that a bit from being a biology geek. That said, I’m still not a physician, so take this as a discussion of a topic, not medical advice.
Americans have gotten very used to being able to hang out in a nice air conditioned space when the heat rises. If the air conditioning becomes unavailable, being so used to it becomes a problem.
There is another article here on 3BY about strategies for not overheating, and you can read it by clicking HERE. This article is actually a “second edition update” in the PrepperMed series, and it focuses on how to recognize when overheating has occurred, and what to do about it if ‘Call 911’ isn’t a viable option.
If you feel like the cactus, but you’re not wise about keeping cool…
…You could explode into a cloud of dust like this poor guy. Or (more likely) suffer heat injury.
There are three stages of heat injury, each worse than the last. They are:
- Sweated too much: Heat cramps
- Sweated way too much: Heat exhaustion
- Couldn’t sweat enough: Heat stroke.
Hey look, they even arrange themselves in alphabetical order for our convenience! Cramps, exhaustion, stroke.
The basic biology of it: We sweat to cool ourselves. In order to coax the water to the surface so it can evaporate and cool you, you lure it by pumping out ions. Ions, also called electrolytes, are the things that make up salts. So when you sweat you lose water and electrolytes. Your brain and muscle cells work by moving electrolytes around, so losing too many electrolytes fouls up brain and muscle function. The water you lose comes from the blood, so if you lose too much of that there’s too little blood left, blood pressure drops, and there’s not enough circulation.
Heat cramps
Heat cramps occur when you’ve been sweating a lot to cool yourself, and it’s worked so far, Yay! But you’re running low on water and/or electrolytes now. That gives your muscles an ‘itchy trigger finger’ as it were, and cramps result. Diagnosing this one is not brain surgery. “Oww Owww, big painful knot in my muscle and I can’t move the leg right!” The smart money is on cramps. The cramps are mostly likely to hit at night after a day of lots of work and sweat. Mine lie in wait until the drop in blood flow that comes with almost falling asleep, then a slight change of position and they Attack!
For more on keeping your electrolytes where they need to be, you can give this podcast a listen:
Heat exhaustion
Heat exhaustion comes strikes during exercise. It comes from the body struggling to cool itself, and getting a little desperate about it. The skin gets a pale and moist, the heart races, the person may be dizzy and disoriented and definitely feels weak. He might feel nauseated, too. There’s a lot of sweat. Heat cramps may co-occur. Standing up is likely to provoke faintness and tunnel vision … that’s about one half breath away from passing out.
Drink plenty; but there’s no point in trying to drink more than about a liter an hour, as the you can’t absorb it much faster than that.
For electrolytes, I find salty foods plus water more effective than sports drinks. My subconscious seems to know this; I’m normally not a food salter but after a day of sweaty work you’d have trouble prying the salt shaker out of my hands.
For heat exhaustion, the big thing is don’t be stupid and just try to ‘man up’ or whatever and push through it. It’s not a ‘push through’ thing; willpower will not trump too little blood to the brain. A seat in the shade with fashionable accessories such as wet towels on the head is the smart move. Those high-tech cooling towels are helpful, especially when electricity-based cooling is not an option. If you disrespect heat exhaustion it can lay you out or push you into heat stroke.
Big strong men get heat injury too…actually more easily than the scrawny but heat adapted.
Heat stroke
Heat stroke occurs when the cooling mechanisms have been insufficient and body temperature’s gone dangerously high (104 F or more). The heart races, breathing is rapid, the skin is deeply flushed as the body tries desperately to dump the heat. The person may sweat a lot to start with, but the skin goes dry as shutdown begins. Headache, nausea, and vomiting may accompany as signs of the physical stress.
The brain is starting to malfunction like an overheated computer, so changes in mental state occur …and it ain’t a change to being able to calculate cube roots in your head. Confusion, poor coordination (shows up as slurred speech), poor decision making, agitation, delirium, seizures, and coma follow. Death is not that far behind coma, so this is not a path you want to be on.
If emergency med help is available, call it. This is not something to play with. But if the person’s alone, they better hope for a cloudburst. It’s all about cooling; and cooling on hot conditions is all about getting out of the sun but not the wind and getting the person wet. Wet cloth is great if there’s a wind, with the cooling towels being a bit better than regular cloth. Put the cloth on the head, neck, wrists, and groin especially, because of all the hot blood close to the surface in those places.
If ice is available … now’s the time! A kiddie pool full of fresh pulled well water would be a blessing. Any diver knows that water that’s even a little cooler than the body sucks heat away amazingly: Water conducts heat away 25x more efficiently than air.
Now That’s better! Thanks to By U.S. Army [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons for the image
Bonus coverage:
Besides these ‘big three,’ there’s one other heat-related problem that gets overlooked: Potassium depletion. Potassium is an electrolyte. You lose it when you sweat; not as much as you lose sodium, but some. If you’re being careful about replacing salt (with its sodium and chloride ions) and water, it might be potassium that runs low first.
Muscle weakness accompanied by a tremor is the main early symptom. That’s as far as it usually gets from heat injury. (Kidney problems or extreme vomiting or diarrhea can mess up potassium more deeply, but that’s not today’s problem.) The doc who takes care of my sports teams gives us potassium gluconate tablets when we get ‘the quiver’. Lite salt (a 50:50 mix of sodium chloride and potassium chloride) can be used in place of regular table salt, including for cooking; it may be a good choice when you’re working in the heat a lot.
Those of you on meds:
Some of the diuretics given to lower blood pressure or help with kidney issues have a side effect of making you keep potassium. If you’re on these drugs, supplementing potassium can be a terrible idea. Talk to your doc or look up the information on your meds if you’re unsure. Potassium from food in any halfway normal diet has never been a problem so long as I know.
Also, some of the meds for high blood pressure keep your blood volume down, making you more susceptible to heat exhaustion from low blood volume. Salty’s doc tells him not to take the diuretics on days where lots of bike riding is planned in hot weather.
Other medications for blood pressure or heart diseases (the beta blockers) will interrupt the rapid pulse that usually comes with heat stroke and heat exhaustion. They can also block your ability to constrict your blood vessels to deal with dropping blood pressure from water loss. If you’re taking a beta blocker, these heat problems are more likely to occur and harder to spot. Forewarned is forearmed, right?
Lite Salt has as much potassium as sodium and may be used in place of ‘normal’ salt.
Prepping for heat injury:
Once again, the best way to win is not to play. Thin and breathable but long-sleeved shirts coupled with wide-brimmed hats keep the sun off and help sweat evaporate. Cold packs in the med kit are useful for heat injury a well as sprains. Having water to spare and that bandana that oughta be in the kit anyway are good. So is knowing how your meds are likely to impact your heat tolerance. A cooling towel might be worth it, if space and weight aren’t at a premium.
I always carry a small ziplock style bag full of mini pretzels when traveling in the summer heat, as well as a few bottles of water. If I know I’m going to be doing any walking or working outside in the heat, I also bring a cooler with a bunch of cold water AND a bottle of oral rehydration solution. The bottle of ORS is in case I was sweating too much, so I can avoid getting shaky from dehydration and/or electrolyte depletion.
I was able to pick up a backup that is a cooler bag, so on hikes I wear that. I fill it with a 1-liter bottle that I turned into an ice pack (by freezing as is) then cold water fills the rest of the space. Snacks go in an upper pocket on the bag. And if I manage to drink all the cold water, the ice bottle should be melting by that point so it’s drinkable too. On vacation, I bring the cooler backpack and a full bag of snack style foods whenever we’re driving around an unknown area. Usually a couple of days worth of calories, and about a day’s worth of cold water.
Don’t want to risk heat issues…it gets harder to deal with as we age. But as I like to say: getting old stinks, but it beats the alternative. 😛