Researchers at uOttawa suggest fans may not cool you down in extreme heat

Seniors spend time near a fan a in this Thursday, June 9, 2011 file photo. (Steve Ruark/THE ASSOCIATED PRESS)

Fans do not provide effective relief from hot and humid weather in Ottawa and across Canada, according to new research.

Researchers at the University of Ottawa are calling on public health officials to improve accessibility and sustainability of air conditioning and other cooling solutions for people to beat the heat, saying fans do not "significantly lower" your body's internal temperature during extreme weather.

"Fans are often recommended as cheap and easy solutions, but this study suggests they might not be as helpful as previously thought," uOttawa said in a media release on Thursday, declaring, "fans are not a magic bullet for beating the heat!"

Post-doctoral fellow Robert Meade led the research, which was conducted by the University of Ottawa's Human and Environmental Physiology Research Project.

"Fans do improve sweat evaporation, but this effect is not strong enough to significantly lower your body's internal temperature when it's already really hot," Meade said in a statement.

"In older adults, who may have a reduced ability to sweat, fans provide even less cooling benefits. In fact, even in younger adults, fans only provide a small fraction of the cooling power of air conditioning."

The study recommends health organizations and public health units place an emphasis on "providing access to alternative cooling solutions," and on exploring ways to make air conditioning and other cooling methods more accessible and environmentally friendly.

A statement from uOttawa says while fans are good at providing air circulation and may work in moderate temperatures, they are not effective in extreme heat. Meade says public health units have a role to play to help keep people cool.

"Keeping indoor temperature cool is important for vulnerable individuals, but cooling strategies like air conditioning can be costly and harmful to the environment. It is crucial that we improve the accessibility and sustainability of air conditioning and other forms of ambient cooling to protect those in need," Meade said.

"Fans can still have an important role in this, since they can be effective for cooling at lower temperatures, meaning we don’t have to set our air conditioners so low. However, when it gets really hot, a fan alone is not going to cut it."

Meade and researchers at the University of Ottawa conducted the research using "human heat balance" modeling techniques, according to the university.  Researchers were able to estimate core temperature under a range of conditions and modeling assumptions, and compare the expected effects of fan use under a wide range of scenarios.

"Results from the 116,640 alternative models we produced in sensitivity analyses indicated that fans likely do not significantly reduce core temperature in high heat, or match air conditioning cooling," Meade said.

"Comparisons with more advanced modeling techniques and laboratory heat wave simulations supported this conclusion."

The study was published in the Lancet Planetary Health Journal.