Ceiling Fans May Increase Heat Strain When Temperatures Exceed 31°C

Recent research from Griffith University highlights the limits of using ceiling fans as a cooling solution during high indoor temperatures. The study focused on older adults resting indoors in heat conditions of 31°C with 45% humidity, similar to those experienced during summer in Southeast Queensland. Researchers found that while ceiling fans could slightly lower peak core body temperature by 0.2°C and reduce heart rate by five beats per minute, they did not fully prevent the physiological effects of heat stress. Under these conditions, core temperatures rose nearly 1°C, and heart rates increased by 22 beats per minute, indicating that fans alone are insufficient for health protection in sustained heat scenarios.

Dr. Fergus O'Connor from Griffith’s School of Allied Health emphasized that ceiling fans are most effective when used early during heat exposure and at ambient temperatures below 33°C. Combining fans with air conditioning set around 26°C provided a more effective cooling strategy, reducing electrical consumption while safeguarding health.

However, the study also warns about the potential risks of fans at higher temperatures. When indoor heat surpasses 40°C, fans can exacerbate heat strain, converting indoor environments into convection ovens that lead to fatigue, dizziness, cognitive impairment, and heat-related illnesses. As climate change causes more frequent and intense heat waves, the importance of sustainable cooling options becomes critical, particularly for vulnerable populations such as older adults.

The findings underscore that while ceiling fans offer some relief, they should not be relied upon as the sole cooling method in extreme heat. Public health recommendations should prioritize effective interventions, including access to air conditioning, especially through government programs aimed at protecting at-risk groups from heat-related health threats.

This research was published in the Journal of the American Geriatrics Society and highlights the need for comprehensive cooling strategies to adapt to our warming climate, with an emphasis on protecting the health of older adults during heatwaves.