A runner's heat index: Blessing or curse?

Yes, when I most recently blogged, I linked to a motivational poster that scolded runners who whine about the heat. So what am I gonna do today? Write about oppressive heat, of course.

One of the Runner's Digest entries on RW Daily linked to a tongue-in-cheek post titled "The runner's heat index." The author included a serious chart — one that combines temperature plus humidity to tell you how safe or dangerous running under certain conditions is — and suggested that math-savvy runners create one more specific to them.

Miss Zippy proposed a formula adding temperature, humidity, miles run, pace and time of day, possibly subtracting degrees depending on how hydrated you are. If I were actually qualified to build said formula, I'd drop time of day in favor of whatever figure measures sunshine (maybe UV index?) and the type of terrain. During yesterday's mid- to late-morning bike ride, it was remarkable how much different I felt on the forested parts of the Neal Smith Trail as opposed to the wide-open ones.

Which reminds me that wind — speed and temperature — would be other important variables in this now-very-complex equation. (I'd need to build an app where you just plug in a few numbers in order for anyone to use my hypothetical formula.) Thus far, though the humidity in Des Moines makes me perpetually droopy, the breezes around here are basically perfect: gentle and cool, as opposed to the fierce and blazing ones I encountered in the Rockford Half Marathon.

Joking aside, I think I'm glad I found this blog post. I say "think" because it doesn't exactly endorse some of the running-related decisions I've made.

For example, it confirms my decisions over the past two days not to run at all — highs were in the upper 90s, and it's safe to say the humidity was high enough to warrant "extreme caution" — and, over the past week or two, to run at night when the temperatures fall into the 80s.

But on the other hand, it's like a delayed scolding for runs that, while not resulting in heat stroke or heat exhaustion or dehydration, were technically ill-considered. Example: Fourth of July midmorning run. And let's face it, when you're a heat-hating, fair-skinned late-comer-to-running, do you need any more encouragement to sit on the couch?

I know, I know. Knowledge is power. Forewarned is forearmed. Always be prepared. Still, I can't help wanting to use that chart as proof of my toughness afterward, instead of arguments for joining a gym (UGH).