2 summers ago, I was validating the effectiveness of my research regarding my copy of Tailwind/Scratch drink mix formula by riding the road during 1-4 pm. I was testing the very myth that hydration prevents heat stroke. After the ride, that night I found that my body's own temp regulation was not really functioning at all. My temps stayed elevated for a long period of time, especially my skin temp. I was expecting some sort of heat stroke-like effect from the test, so I calmly remedied it by regularly wiping myself down, especially my forehead, with a wet wrung-out washcloth regularly until I returned to normal. It took several hours, but was fully recovered by the next day, with bed time a little delayed.
Gist of the story, is that you can still get heat stroke, despite being prepared with plenty of hydration. For context, I was riding with very light roadie-style clothing with a lot of skin exposed, averaging at least 15 mph for the duration, with a couple ~15 min breaks mid-ride.
Digest of "sciency wisdom" that I've learned that may serve as advice:
- body temp regulation is the name of the game.
- maximizing ventilation is foolish when the environment isn't cooler than your body. The air temp could be measured as low as 20 F by a thermometer, but the same thermometer exposed to the sun can register 80 F; this is why outside thermometers like bank signs always report higher temps than the weatherman. Don't underestimate the heat from infrared radiation from the sun (not only direct, but also reflecting off of the sand, your bike, off the ground and again off the underside of clouds, etc), rocks, asphalt, etc.
- Sweat is the primary natural way for our body to regulate its temp, mostly through an effect called evaporative cooling. You know that feeling, when you let a breeze (or AC) hit your sweaty clothes... exploit this effect wisely.
- Light colored and loose clothes is often recommended*, but like the food pyramid**, these guidelines were intended for specific user groups. Black colored clothing actually has advantages in certain high temp conditions...
* useful for summer picnics, not so much for intense exercise (especially not at higher speeds)
** useful for physical labor and endurance sport lifestyles, terrible for sedentary lifestyle
The last point deserves some elaboration. It should be common sense that things appear white because it reflects a wide range of the color spectrum of light, as does silver, while black appears black because it absorbs a wide range of light's color spectrum. Heat comes from infrared, which is not part of the visible color spectrum (infrared <- ROYGBIV -> Ultra violet). Here's the kicker: black absorbs heat from the body, while white reflects body heat. They both cool at a similar rate (trivia: metallic/silver cools slower). With active cooling coming from normal riding air flow and body movement, black colored objects will exchange higher heat/temps from the body to the cooler temps outside better than white.
Wait, but that's not all... white also allows more light to penetrate. You may notice that when wet, a white t-shirt becomes much less opaque than a black one. This is allowing much more harmful UV rays to damage your DNA (your body's blueprints)--your white blood cells devour all these damaged/mutated cancerous cells with a ~99.999% effectiveness rate, but that 0.001% can be something to worry about--the effects of the white blood cells work shows as a sun burn, and you may have noticed how spotty they are. Your body "tans itself" to absorb UV, partially preventing future UV rays from penetrating deeper (my sympathies to people with light colored skin). UV also ages your skin, if that matters to you.
For a limited time only, if you act now... Mikie can argue that air flow over his spandex shorts that dispersed his sweat over a wide area is way better than the same airflow over bullets of sweat dripping down bare skin, under neon yellow baggies that is blocking the air flow (and retaining an insulating layer of high humidity). Loose clothing doesn't make efficient use of the effect of sweat if it's just letting it drip. Use your entire surface area of your body as a heat sink. Keep the water spread like mist to speed up evaporation and boost the impact of the evaporative cooling effect.
---end science-related dump---
Too long, didn't read? A guy dressing up as a ninja to bike in the summer is not as hot/stupid in that suit as you may think, compared to going "suns out, guns out". To learn why, you know what to do ^^^ *wink* *nudge*
Disclaimer: this post is not 100% "scientifically accurate". They are just my observations and should be validated/peer reviewed before investing any belief into it. Researching tthermodynamics, Plank's law, etc should get you started.
