Cities may need to be redesigned for extreme heat

The hotter it gets, the less people want to move their bodies outdoors, according to recent research in the International Journal of Biometeorology.

Why it matters: While the finding may seem obvious, it's just one example of the implications extreme heat has on health and wellness — and why experts say cities will need to adapt.

Details: The authors of the study used electric counters to track hourly pedestrian and cyclist traffic on a popular trail in Austin, Texas, looking for the connection between the temperatures and trail use.

• Pedestrians — at least those in Austin — were most likely to use the trail when the temperature was between 45°F and 81°F with peak use at 63°F. Cyclists were most likely to use the trail when temperatures were between 59°F and 91°F with peak use at 81°F.
• In summer, pedestrians were more likely to use the trail until temperatures reached 81°F and cyclists were more likely to use the trail until temperatures reached 91°F.
• Applying two greenhouse gas emissions scenarios and the expected impact on extreme temperatures, the study projected overall trail use would decrease by up to 17% by pedestrians and by up to 5% by cyclists by the mid to late-century.

What they're saying: As temperatures hit heat extremes more often, cities may need to consider interventions, such as creating "cool corridors" — adding green space, tree canopy or retractable shade structures — to encourage physical activity.