7.02.2013

Too Hot, Maybe Not…Cover-Up to Cool Down

This past weekend I rode to Shiner, TX with my local HOG Chapter.  The temperature in the afternoon registered 107 along portions of our route and many in our group began to feel the effects of the heat.  We adjusted our ride plan and took frequent breaks to give our bodies a chance to cool down. At one point, we even huddled inside a walk-in beer fridge…giving a whole new meaning to the phrase, “just chillin”.   As we sat in the fridge, I wondered, “Can it ever be too hot to ride?”  I did a little research and here’s what I found…
Individually our tolerance to heat varies but physiologically our bodies all regulate temperature the same way. Our bodies try to maintain a core temperature of 98.6 degrees primarily through radiation, convection, and evaporation.
·    Radiation - We gain or lose heat when we’re in close proximity (but not in contact) to an object that is either warmer or cooler than our skin temperature.
·    Convection - We gain or lose heat when our skin is exposed to the surrounding air.  We lose heat if the air temperature is cooler and gain heat if the air is warmer.
·    Evaporation – As our core temperature starts to rise, we begin to sweat.  The body then cools as the sweat evaporates from our skin.

When the air temperature is below our core temperature all three processes work together to provide cooling.  However, once the air temperature reaches about 95, radiation and convection work against us and can actually make us hotter.  At that point, the only way our body has to regulate temperature is through evaporation.  
For bikers, this can be problematic because riding “exposed” through hot air can cause your sweat to evaporate so quickly that evaporation becomes ineffective for cooling as well.  With the body’s methods to regulate heat effectively shut down, we quickly become overheated and begin to experience symptoms like dizziness, nausea, and muscle cramps.  Continued heat exposure can lead to heat exhaustion and heat stroke.
So does this mean 95 is the magic too hot to ride number?  No, because we can cover-up to cool down.  By wearing more clothing and covering our skin we can make evaporation work as Mother Nature intended.  Covering-up as the temperature rises slows down the evaporation of our sweat allowing it to transfer heat more efficiently.  When the temperature climbs past 95 and into the triple digits, exposed skin is a bad thing.  While it’s counter-intuitive to add layers in the heat of summer, just think about those who live in desert environments across the world…you don’t see them trekking around wearing short-sleeves and tank tops now do you?
Once you’ve covered-up (and even if you don’t) you need to ensure you’re drinking plenty of water to replace the fluid you lose when you sweat.  On a long, hot ride, you need to drink as much as 40 oz of water/sports drink per hour to stay properly hydrated.  By staying hydrated and covering-up, you can ride “comfortably” as the temperatures climb.  Follow these guidelines to safely extend your riding into triple digit temperatures:
·    Cover-Up – Wear a mesh or lightweight textile jacket with the vents fully open (for additional cooling, wet your shirt or wear an evaporative cooling vest). Additionally, wear a helmet that covers your face or try a water soaked bandana to keep your face covered from the hot air.
·    Hydrate – Drink fluids (40oz/hour)… remember, alcoholic beverages don’t count--they will dehydrate you.
·    Take A Break – Find some shade and sit for a while…walk-in beer fridges work great.

Now Live Free and Ride Hard knowing that high temperatures don’t have to stop you from enjoying a great ride. At the end of the day, only you can really answer the question, “Can it be too hot to ride?” 
Sources
Temperature Regulation of the Human Body - http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatreg.html
Riding Motorcycle in Extreme Heat - http://motorcycleinfo.calsci.com/ExtremeHeat.html
Tips for Staying Cool on Blistering Hot Motorcycle Rides - http://www.usridernews.com/tips-for-staying-cool-on-blistering-hot-motorcycle-rides/
Beat the Heat While Motorcycle Touring This Summer - http://www.thelostadventure.com/beat-the-heat-while-motorcycle-touring-this-summer

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