What are we waiting for? Fans help you beat the heat and save the planet!
This series addresses things we can all do today to improve our well-being and help protect the environment.
BY Jonathan A. Patz, MD, MPH
May 16, 2025
Last year was the hottest on record globally and this year is on a similar track. As we head into the hottest part of the year in the northern hemisphere, everyone is looking for the most cost-effective ways to stay cool.
Why worry? According to a 2023 World Meteorological Organization report, heat exposure is the deadliest of all extreme weather events. Here are just a few reminders of what extreme heat can do to your body:
Heat exhaustion, which can lead to heat stroke if not treated, can cause critical illness, brain injury, and even death.
Heat increases the production of ground-level ozone that leads to worsening asthma and COPD symptoms for those who struggle to breathe.
Dehydration can lead to kidney injuries and blood pressure problems.
While the simplest thing many people do in extreme heat is to head to the thermostat and select a temperature to keep your home comfortable, there may be a better solution that not only keeps you cooler but lowers the need for electricity from fossil fuel power stations.
Turn on your fans. A fan-first cooling approach is gaining steam in many areas of the world. Moving air with electric fans requires about 30 times less electricity to operate than a standard central air conditioning unit. Because a large share of our power grid is still reliant on climate-damaging fossil fuels, boosting fan use over air conditioning can also help reduce air pollutants.
A 2022 Australian case study found that ‘fan-first’ cooling could reduce annual electricity demand from air-conditioning by more than 70 percent. Instead of turning on air conditioning when the internal temperatures hit 23˚C (74˚F), air movement from fans makes it possible to wait until internal temperatures hit 26˚C (80˚F) before individuals feel the heat. Using fans alone compared with air conditioning alone resulted in a 76% reduction in energy use (from 5592 GWh to 1344 GWh) – and reduced associated greenhouse gas emissions (5091 kilotons to 1208 kilotons).
One caveat: If you live in an area that has very hot-arid conditions, fans may not work as well as they do in areas with higher humidity. According to the EPA, anything below 20% humidity is considered very dry.
But for many people who may experience extreme heat this year, a fans-first approach may be just the ticket to a cooler home, lower energy costs and a cleaner environment.
References:
State of the Global Climate 2023. World Meteorological Organization.
The potential for indoor fans to change air conditioning use while maintaining human thermal comfort during hot weather: an analysis of energy demand and associated greenhouse gas emissions. Malik A. et al., The Lancet Planetary Health. April 2022.