#US should consider ‘stay-at-home’ cooling options during pandemic

• In 80 of the 105 metropolises examined electric fan-use would have resulted in effective cooling on every summer day over the last 20 years.
• In only 3 of the 105 metropolises assessed (Phoenix and Tucson, Arizona and Las Vegas, Nevada), this method would not have been effective more than five percent of the time.
• This means 65 percent of the US population (200 million of the 222 million residents living in these most populous metropolises) could have effectively used this strategy to keep cool on 100 percent of summer days.

They conclude that this solution could be potentially recommended by health authorities as a safe and effective stay-at-home cooling strategy across vast swathes of the Northeast, Southeast and Midwest regions of the United States, as well as the West Coast.
The researchers acknowledge that while the modeling is conservative (based on the physiology of an older adult) it can only show when fans would or would not be effective based on climate. As with many public health interventions, an individuals’ response to the cooling strategy may be influenced by their health status.
The modeling explained:
Based on previous work published in JAMA and Annals of Internal Medicine the authors modeled the humidity-dependent threshold temperature under which fans and self-dousing provide a beneficial cooling effect.
The previous trials conducted on participants in a climate-controlled chamber show that that in hot, humid conditions fans lower core body temperature and cardiovascular strain and improve thermal comfort. However, fans can be detrimental in very hot, dry conditions.
These data were analyzed alongside historic weather data (temperature and associated relative humidity) recorded at any point over the last 20 years (2000 to 2019 inclusive) for 105 of the most populated metropolis areas in the United States.
First author and Ph.D. student Lily Hospers said: “Importantly, this research proposes a potential cooling strategy that can be used at home during the current pandemic, therefore circumventing the need for potentially risky excursions into public spaces and expensive home-based air-conditioning.”
Declaration: The authors declare no competing interests.