Going out for a run early in the morning with 20 deg F ( -7 Celsius) temp (with windchill)? … I can deal with that…
Finding slippery treacherous icy stretches on the trail while running? … that is okay with me too…
In spite of clipping at a fast (by my standards) 8 minute mile to keep the body warm, getting passed by a couple of runners at break neck speed? … well, I can accept that too…

But when those runners pass by me wearing just a pair of shorts and half sleeve running t-shirt – in 20 deg F, mind you!! – NOW, that is when I have to stop and throw the red flag!! That is insane!!!!