You will lose to the heat every time that you under estimate it.
Practical Applications of Preventing Heat Exhaustion and Stroke by Robert Finlay of Kayak Lake Mead
This article is written with the purpose of helping adventurers deal with the extreme heat of the desert.
It's fine to read an article about heat exhaustion and heat stroke but quite another thing to absorb that
information and follow its guidance. I will use some of my summer and survival experiences in the sands
of the Mojave Desert, on Lake Havasu, and on Lake Mead as examples of what or what not to do.
The gist of my article Hot Weather Kayaking and Adventure is...if you DON'T regulate your body's heat
gain YOU WILL suffer a heat injury of exhaustion or even stroke. Now let's look at what that really means if you are kayaking, walking in the desert, or adventure racing in the heat. And let's see how you
can prevent it.
Warning: The methods of preventing a heat injury are deceptively simple. So simple in fact that they are
continually overlooked by adventurers in the desert. This is why... DEATH BY HEAT EXHAUSTION /
HEAT STROKE IS A COMMON OCCURRENCE IN THE DESERT.
If you are an adventure racer, hiker, or kayaker AND are planning an adventure in the desert's heat,
please read carefully and follow the guidelines of this article.
My method for coaching heat injury prevention is to over simplify the message. This is important because...heat injuries are a little like drinking vodka...you don't know you are effected until it is too late.
You have to KNOW what the heat will do to you BEFORE you venture in to it SO YOU CAN prevent
heat exhaustion AND NOT become a casualty.
All heat gain sources are significant. This battle against becoming a heat casualty is simple math...gain
more heat than you are losing and you lose...lose more heat than you are gaining and you win.
Considerations of Kayaking in the Heat:
Paddling in a hot air and warm water environment.
Heat Facts... To be concerned with while kayaking. Your body will gain heat in the summer on the water while paddling by (a) direct solar exposure, (b) the reflected light off the water, (c) any lack of wind to carry away heat by convection, and (d) conduction from anything that you touch that is hotter than you (your black kayak seat, your red PFD, your black carbon fiber paddle shaft, a dark hat on your
Hot air concerns: (a) If the air is hotter than your body you will NOT lose heat by radiation to the air.
(b) If the air is not moving you will not lose heat by convection.
Warm water concerns: If the winds have not been blowing causing convective heat loss to the body of
water you're on and it is a non moving body of water like Lake Mead you can expect the water to be warm.
Lake Mead can get warm in the middle of the summer. Sometimes water that even feels cool is down a
body length or so.
This means that on Lake Mead or similar desert waters you WILL NOT COOL OFF (at least not very quickly) by getting in the water!
Desert water advantages and dangers: Water has a higher specific heat value than earth and rocks.
This means that water can absorb lots of heat from the sun before its temperature rises as opposed to
earth and rock which get hot quickly in the sun. This means that kayaking on a desert lake in the summer is in fact cooler and it will feel cooler than hiking on land over rocks, but that is the trap. Kayaking in the hot desert is still dangerous if you are gaining heat faster than you are losing it.
Guidelines for Preventing Heat Exhaustion while Kayaking:
1) If practical...kayak at night. You will be cooler at night primarily because (a) direct solar heat gain is
zero and (b) the air is cooler thereby allowing heat loss through radiation.
2) If it is not practical to paddle at night, then paddle in the early morning and early evening.
Both the land and water have radiated their heat to the air all night long and so the morning is cooler.
By late afternoon, the land and water are at their maximum heat gain but the sun is lower in the sky and
this lower angle means more of the sun's light is reflected off the atmosphere meaning there is less direct
solar heat gain on paddlers and other creatures.
3) IMPORTANT: Paddling during the day...stay wet. Get out of your kayak and take a dip occasionally
in all your clothes. Water will conduct heat away fast. And by being wet you create a powerful evaporative process that will keep you cool. We stop right in the middle of the lake to get wet, see our article on the kayak wet re-entry.
4) Drink water to insure that you do not become dehydrated. If you are dehydrated then you cannot sweat properly. Sweating is the body's #1 process to keep cool. It is a process of losing water. But it is a process of evaporation which is the process of cooling.
Tip: I habitually sip my water every 5 to 7 minutes from my water bladder. Without a bladder I would need to stop paddling to drink.
) Include in the process of drinking water an electrolyte replacement plan AND stick with it. I usually
keep just pure water in my bladder. I will then have additional bottles of water with an electrolyte in them
and or some electrolyte pills in a double zip-loc (there is nothing worse than a mass of wet dissolved
electrolyte pills in your single zip-loc bag).
Tip: I have developed the habit of reminding myself every 15 to 20 minutes to replace electrolytes. I used
to use the timer on my watch, but now it is an ingrained habit.
6) Dress in loose fitting clothes that have venting. Loose fitting clothes allow air movement, air movement allows heat lose by convection. Venting allows the air that has gained heat to vent away from your body.
7) Dress in light colored clothes. Light colored clothes reflect the sun's light. Therefore less light is transformed into heat on the clothes you wear.
8) Cover yourself completely. Direct heat gain on your body is direct heat gain on your body.
9) If YOU can think of anything else, INCLUDE it into your heat exhaustion prevention plan.
A Paddle in the Desert Heat...
From the north end of Topock Marsh to the southern end of Lake Havasu in July, 50 miles in 10 hours. By the mid to late afternoon it was hot, something like 122 degrees F in the City of Lake Havasu. By the way, this is a very special desert paddle...with the volcanic scenery and the abundance of interesting hikes to do in Topock Gorge. It is worth many return trips.
Here are some things I did right and some things I did wrong.
1) I started paddling 0600hrs, a fairly early start, but not early enough.
2) I had fresh water to drink, but not really enough and no way to treat the lake water.
3) I maybe had enough food to eat, but no extra electrolytes.
4) I wore light colored clothes and hat, but no scarf to cover my neck (see picture above).
5) In the afternoon I got out of my kayak and into the water a couple of times to cool off, but not often enough to keep my body temperature down.
Summary: By the end of the paddle I was glad I had someone to pick me up. I had not prepared
correctly for the effort of this paddle adventure in the desert heat.
Considerations for Hiking in the Heat:
Hiking in a hot air and hot ground environment.
Heat Facts... To be concerned with while hiking. All the heat facts presented for desert kayaking apply
to desert hiking with some additional dangers.
Hot Ground Concerns:
Even though the water you're kayaking on in the summer is warm, it is water and if it is cooler than you,
you can conduct your heat to it. While hiking over the land you will have no such luxury. On land, you
must consider extreme heat gain by radiation and conduction and consider carefully the means by which
you MIGHT be able to cool down.
Your body's heat gain by radiation: With a low specific heat value, earth and rock will gain heat
quickly in the sun. The ground in fact will get MUCH HOTTER than the ambient air temperature and
therefore, the ground will radiate heat to the air...lots of heat to the air.
If the advertised air temperature for a local area is say, 110 degrees F; you can expect the ground by
mid-afternoon to be maybe 150 degrees F and the air temperature at your knees to be about 140 degrees
F and at your head level to be about 130 degrees F.
These extreme temperatures are a far cry from the reasonably hot temperature of 110 degrees F that you
heard predicted on the weather channel that morning.
Your body's heat gain by conduction: The above example of 150 degrees F for ground temperature is
actually conservative; in fact ground temperatures can easily reach 175. Heat will be conducted into your
body by the contact your feet have with the ground.
Hot air concerns: With air temperatures over 130 degrees F, the air that you breath becomes
dangerous. (a) You are introducing another source of heat gain into your mouth, nose, throat, and lungs.
(b) This extreme hot dry desert air is another source of dehydration in your mouth and lungs. (c) As you
breath hot air you are introducing more heat to your body internally. The evaporative cooling process
that occurs in your lungs will be thwarted by breathing hot air.
Guidelines for Preventing Heat Exhaustion while Hiking:
Include the above mentioned kayaking guidelines as they pertain to hiking in the desert.
Preventing heat gain:
1) If practical...hike at night. You will be cooler at night primarily because (a) direct solar heat gain is
zero and (b) the air is cooler thereby allowing heat loss through radiation. See my article about navigating
2) If it is not practical to hike at night, then hike in the early morning and early evening. In addition to the
above reasons for kayaking in the morning and evening, on land the shadows are longer. Therefore, the
small amount of shade offered by the small brush or the sides of gullies is enhanced.
3) IMPORTANT: WATER TIPS to STAY ALIVE - Drink water and err on the side of carrying too
much water. (a) An athlete only needs 28 or so fluid onces to stay properly hydrated during competition.
That athlete however has water at aid stations to splash on clothes and head or to soak hat and
handkerchief in. You will not have these luxuries. You will need water for drinking and cooling. (b) On a long all day hike in the hot desert, you will need more than one gallon per day. (c) One gallon weighs 8.3 pounds, do not let that information deter you from carrying more than one gallon. You must carry enough water to get you to the next water point AND if that means carrying 3 gallons (25lbs of water), so be it.
Hot Tip: Use ONE water bladder and carry your additional water in SECURE screw lid containers. With
pressure against a water bladder, such as when it is stuffed in your back pack, it will leak through the
nipples. This means you will lose water AND then you will lose. 4) Have a well thought out food and water plan AND include electrolytes in your refueling and re-hydrating plan.
5) Dress in loose fitting and light colored clothing AND cover completely.
Hot Tip: Breath through a wet cloth to pre-cool the air before introducing it to your mouth, nose, throat, and lungs.
6) IMPORTANT NOTES FOR FEET - (a) Keep your feet lubricated. This will help insulate your feet plus you will not need to sit down on the hot ground for blister foot care and the friction heat from blisters will not be another source of heat gain. (b) Wear light colored ankle gaiters. This will help to insulate your feet and by keeping your feet free of pebbles and sticks you will not need to sit down on the hot ground for blister foot care. (c) WEAR INSULATED SOCKS! This will help insulate your feet from the extreme ground
Hot Tip: I wear neoprene socks during hot desert hikes. Because of the insulation value, this keeps my
7) IMPORTANT: USING SHADE to STAY ALIVE - Stop hiking occasionally and find shade. (a) When you stop hiking, you stop producing heat by exercise. (b) And when you find shade you are at least stopping the direct heat gain from the sun. (c) Take a look at the top picture. That is typical Mojave terrain (sand and rock) and vegetation (brush, Creosote bush, and Joshua tree). There is precious little shade available. But some shade is better than no shade. Find one small patch of shade at least as big as your head and get your head in it. (d) However, the ground is still hot and conduction of heat to your body will be a concern. Hot Tip: Put a space blanket down first, then an insulating pad and then lay down on that.
(e) Depending upon how hot you are getting, time your stops every 5 to 30 minutes apart. (f) Have two space blankets in your kit. One for the ground cloth and the second one for a shade cloth. This will insulate you from the hot ground AND create shade AND reflect the sun's light away. You can
quickly create an environment that is 30 to 40 degrees cooler.
Hot Tip: I use a military style space blanket. It has heavy duty ripstop nylon on one side, with reflective
mylar on the other side, and grommets on the sides and corners for tie down points. Make sure to have a
small nylon cord tied on each corner AND carry extra cord for tie downs in strong winds.
8) Use walking sticks on long desert hikes. Whether you personally believe in using walking sticks on
hikes is not important, walking sticks will be useful in erecting shade shelters. If you do not have much
walking stick experience, practice with them a little before attempting a long desert hike. There are subtle
techniques that are worth discovering beforehand.
9) Plan your desert hike to take advantage of possible shade. Gullies and canyons will have shade in the
mornings and afternoons. Be sure to plan your hike to take advantage of that.
10) IMPORTANT: The way points of your planned hike must be the springs, wells, or other possible sources of water through the area of the desert that you plan to walk through.
11) If YOU can think of anything else, INCLUDE it into your heat exhaustion prevention plan.