This article is IMO quite a stretch based on the actual data. > New research from two different groups of thermal physiologists favors the higher temperature l

This article is IMO quite a stretch based on the actual data. > New research from two different groups of thermal physiologists favors the higher temperature limits, especially in humid weather. But the groups don’t agree on a single temperature threshold. One study, published on 6 November in The New England Journal of Medicine (NEJM), reports that fans can relieve stress on the heart in elderly people in humid conditions at 38°C. The other, published on 17 October in JAMA, concluded there was little additional benefit from using a fan above 35°C. The NEJM article is pay-to-read. The JAMA article took older adults, had them sit in a room at 36C, for 8 hours, getting very occasional light exercise and tested three different air movement speeds. The body temperature of the subjects was 38C, independent of fan speed, from which IMO one can conclude approximately nothing other than that the subjects' bodies were warmer than ideal under those conditions. In my personal experience, the effect of air movement and body movement under conditions like this is dramatic. "Resting" (as the study had the subjects do) in the daytime (as the subjects did) is, for me, not so pleasant. Add a fan, and it's less unpleasant. Riding a bike can be very pleasant as long as there's plenty to drink. But I suspect that my rectal temperature would be more or less independent of any of this.