(Gets on hobby horse).
One day I will take a thermometer along and measure how hot it gets where I am running. It definitely gets distinctly more uncomfortable when other people are running next to me and especially if it is a full house. I've had complaints (not to my face, of course) about the amount that I sweat, in spite of my efforts to clean up afterwards. What can I do? Even if I went naked I'd still be too hot and then there would be even more complaints.
The answer is that the cardiovascular machines, like the spinning bikes, should be in a separate room or divided from the weights section (although I also sweat a lot when doing weights). Either that or people who feel cold should wear jerseys for f's sake. I know it's nice to show off your muscles but there are plenty of warm, skin-tight garments available these days.
Armed with my measurements I'll see if I can find some kind of norm (surely from another country like the United States because I very much doubt that one exists in Spain) that is being contravened. On the other hand, we are talking about the same body that organized a 5K race at 5pm in July a few years ago - this actually did break the rules for the maximum effective ("wet bulb") temperature that it is allowed for a running race - and the first two finishers ended up being hospitalized. It was the only race ever that I didn't manage to finish, almost collapsing only 200 meters from the finish line. There is a higher risk of heatstroke in shorter races because you tend to run much closer to your limit.
(Gets off hobby horse)