Hot fun in the summertime

Back in the devil-may-care days of applying “suntan” lotion (and baby oil for the truly dedicated), not sunscreen, I spent hours upon hours at the alter of those magnificent rays.  One particularly memorable day I opted to lounge about on a reflective black roof, to maximize the tanning potential, and swiftly fell asleep beneath the sunny beams.  Hours later I awoke, climbed down, and feeling a bit parched decided to go to the corner store for an ice cream cone and a soda pop (I know, how very tales from Mayberry).  I walked a few staggering steps and promptly fell to the ground, consciousness fading.  I ended the day in a hospital, packed in ice, and suffering from the most agonizing of cramps.  Apparently the body returning to a balanced electrolyte state is rather painful.  Excruciatingly painful, to be accurate.  The blisters that lined the back of my body were gruesome in both appearance and quantity.  That was my only tango with heat stroke.  Stupidly, it was not my last dance with a heat related illness. 
 
Some people are especially prone to heat illness.  Often those people are very young, very old, or very ill.  I am none of the above, yet my body is incapable of properly regulating temperature.  Like the wee little children, I am inefficient at sweating (I’m a low volume sweater, which is handy in nerve-wracking social situations, but not so great for keeping my body chilled) and I have a high metabolic rate (which is awesome for cookie eating, but does generate significant heat).  So I am very hot, in that I produce lot of heat, but I have a lazy cooling system.  This is a particular problem during exercise, when muscle-generated heat can accumulate faster than it is dissipated.  More metabolic heat + inefficient cooling mechanisms + heat generated with running + environmental heat = summertime disaster.  When it comes to running, I survive the summer.  Barely.  I do not enjoy, embrace, or energize.  I survive.  
 
My lack of heat acclimatization is just another sign that I am less evolved than most.  Daniel Leiberman proposes that the unique human ability to run long distances (compared to our relative lameness at sprinting) is a key to our long-term survival and thrival (I made that last word up; don’t blame Leiberman for my bad rhyme).  Evolutionary adaptations that allowed us to run in the heat meant our ancestors could hunt when the yummy game lazed about during the elevated midday temperatures.  Clever human ancesters developed mechanisms to rid us of the heat generated by running, allowing us to run longer and farther than others in the wild kingdom.  We are noticeably hairless (some more so than others), we sweat (some more so than others), and we breathe through our mouths when we run (like when a dog pants, except we can do this when running fast and they can not).   Most other animals would develop hyperthermia (heat stroke) after about 10 to 15 kilometers of running, but we go for miles more.  Hell, we voluntarily run marathons and when that’s not enough we run ultramarathons.  Few other animals run the same long distance over and over again to see if they can do it faster.  Or to see if they can do it in Boston some day. 
 
Without doubt, I would have starved in Pleistocene period, my battle of the fittest eventually lost to a more heat-resistant family line.  Although not everyone suffers as I do in the summer, most runners face an increased risk of exertion-onset heat illness in the heat, especially when combined with humid, weather.  The sunshine is glorious, particularly after a long winter’s rest, but the potential for the heat to hurt should not be underestimated.  More than a run being a slog, a soaring mercury can cause a run to be downright dangerous – if you aren’t careful. 

A weather wise runner is familiar with the types and signs of heat illness.  I’ve provided a very brief overview of the heat illness triad for you, but nothing replaces consultation with a medical professional or at the very least weblog who’s author has medical credentials (assuming those MDs weren’t procured online).  

1. Heat cramps, not surprisingly given the name, are painful muscle contractions, cramps, and spasms.  Cramping typically occurs in the calves or hamstring muscles, but also in the arms and abdominal muscles. 
2. Heat exhaustion arises when the body’s cooling mechanisms (e.g. sweating) are unable to keep up with the increasing core temperature.  Common signs of heat exhaustion include nausea, vomiting, dizziness, fainting, weakness, headache, pale and moist skin, weakened pulse, and disorientation. 
3. Heat stroke, the most severe and worrisome form of heat illness, occurs when the body’s heat-regulating system, overwhelmed by excessive heat, completely fails.  It is a life-threatening emergency and requires immediate medical attention.  When the body’s cooling systems fails, the core temperature rises quickly.  Signs of heat stroke include a core body temperature above 40.5°C/105°F, hot and dry skin, lack of sweating, a very fast pulse, and mental status changes (e.g. confusion, disorientation, delirium).  The mental status changes clearly differentiate heat stroke from heat exhaustion.  Athletes who have exertional heat stroke, however, continue to sweat despite the rise in core temperature.

The more you know friends, the more you know.

Title Reference:  Sly and the Family Stone – Hot Fun in the Summertime.   Single released 1969.