When is it too hot to use a fan?

Embargoed until: Publicly released: 2025-07-30 01:00

Australia; NSW; VIC; SA

Photo by Andrew George on Unsplash

Fans can help you keep cool in hot temperatures, but in dry, very hot temperatures, they will actually make things worse, according to Australian research. The team subjected 58 people to various 3-hour heat exposures, looking at how temperature and humidity impacted the effectiveness of a fan or wetting the skin on reducing body temperature and discomfort. The researchers say in 38C heat with 60% humidity, fan use marginally improved body temperature, and participants reported feeling less warm. In 45C dry heat, however, using a fan increased participants' body temperature, sweating and made them feel more uncomfortable.

Attachments

Note: Not all attachments are visible to the general public. Research URLs will go live after the embargo ends.

Research JAMA, Web page The URL will go live after the embargo ends

Journal/
conference: JAMA Network Open

Research:Paper

Organisation/s: The University of Sydney, Monash University, The University of Adelaide, Montreal Heart Institute, Canada

Funder: This study was funded by grant GNT1147789 from the National Health and Medical Research Council.

Media Contact/s

Contact details are only visible to registered journalists.