Fans won't cool you down when temperature goes up, new study finds

A new study has found exactly how inefficient electric fans are when used to keep us cool in extreme heat. 

Rob Meade, a postdoctoral fellow at the University of Ottawa, led the study. 

"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. 

The study found fans are good at providing air circulation and may cool us down in moderate temperatures, but are not as effective in extreme heat. 

It recommends public health organizations advise against using fans during extreme heat events, especially for older adults and other groups with health risks.

"As we get older we sweat less, so [fans] are going to be less and less effective," Meade said. 

The study suggests health agencies instead focus on providing access to air conditioning and other cooling methods.

'The house felt like an oven'

Kaitlyn Potter has experienced the torment of being unable to cool down during a heat wave.

"The house felt like an oven," Potter said, describing what her non-air conditioned apartment in Old Ottawa South felt like during the summer of 2022. 

"Opening the windows didn't help, and neither did fans. They just moved the hot air around." 

The average internal temperature of the human body is 37 C. An increase of as little as one degree can cause concern. 

If your internal temperature reaches 40 C or higher, you can be at serious risk of heat exhaustion and heat stroke. 

This is of particular concern within certain populations including children, older adults, people with pre-existing health conditions and those experiencing homelessness.  

"Heat doesn't affect everyone equally," said Caroline Metz, managing director of climate resilience and health for the Intact Centre on Climate Adaptation at the University of Waterloo. 

Sustainable air conditioning?

Air conditioning may be one of the most effective ways to combat heat-related illnesses, but isn't environmentally friendly. 

According to a recent UN report, air conditioners emit greenhouse gases and waste heat, which contributes to global warming. Air conditioners also use a large amount of energy, placing additional stress on electrical grids and risking power outages. 

Both Meade and Metz suggested a combination of passive and mechanical cooling measures as an alternative to air conditioning. 

This could include opening windows at night while using a heat pump during the day. 

Meade acknowledged that vulnerable populations may still need air conditioning, but said it should be supplemented with other cooling methods. 

Another issue with air conditioning is the cost. Potter bought a portable air conditioner off Facebook Marketplace for $200. 

This was her only option as a central cooling system can cost thousands of dollars and Potter was unable to install a window air conditioning unit due to the size of her apartment's windows. 

Meade said he will continue to study how to keep people cool and remains hopeful that we can get back on the right track. 

"There is a pathway to what you might call sustainable air conditioning," Meade said.