With spring approaching, you may be thinking about the return of warmer weather. But the evidence is growing and getting more alarming with each passing year when it comes to hot weather. We know from NASA that 2024 was the warmest year on record for the world, with 15 consecutive months (from June 2023 to August 2024) of record-breaking monthly temperatures. We also now have data showing that this January 2025 was the hottest January on record. Perhaps even more alarming, we have substantial evidence that this trend is going to continue, with disastrous results for humans and the planet as a whole. As climate change continues unabated, it’s estimated that extreme heat waves will continue to accelerate so that in the not-too-distant future, as many as 3 billion people across the globe could be exposed to lethal heat waves every year, reaching the limits of what the human body can withstand. Underscoring this dire prediction is a recent study in JAMA predicting extreme temperature-related deaths for later this century. Currently, it’s estimated that over 8200 deaths a year in the US are related to extreme temperatures. Depending upon how well we can control greenhouse emissions, that number could rise to over 19,000 deaths per year by 2065 or even 26,000 deaths per year if emissions remain high. Overwhelmingly, the largest percentage of those deaths occur among older adults.  

We’ve previously addressed the reality that for many reasons, including medications taken, less ability to sweat, and socioeconomic factors such as lack of air conditioning or transportation, older adults are especially at risk when extreme heat waves arrive. Moreover, new data continues to arise to highlight the vulnerability of older adults and what, if anything, can be done to limit the threat when extreme heat is present. Brand-new evidence was just published in Science Advances describing the association between extreme heat exposure and accelerated biological aging in older adults. Essentially, the research found that if you live in a geographic area with more extreme heat days, you’re aging faster biologically. For example, if you live in a location such as Phoenix, where up to half the year is spent at extreme heat levels (at or above 90 degrees F) you may experience up to 14 months of additional biological aging as compared to adults who lived in a cooler climate. To learn more about this study, grab a cold compress and read here.

Other recent research describes additional threats to older adults from extreme heat events. A recent study published in JAMA Internal Medicine describes the particular vulnerability of older adults with Alzheimer’s Disease or Related Dementias during extreme heat events. Perhaps due to being slower to recognize symptoms or being less able to get out of harm’s way, extreme heat events raise the risk of hospitalization for those with dementia who live in the community. In fact, according to current estimates, for every day of extreme heat, at least 5000 additional hospitalizations of people living with dementia may occur. Those living with dementia in Black, Hispanic, or Asian communities may face an even higher risk of hospitalization. This corresponds to yet another recent JAMA study that found that older adults eligible for both Medicare and Medicaid (meaning they are likely living in poverty or a low-income situation) had increased rates of emergency room visits, hospitalizations and all-cause mortality during extreme heat events of at least 3 consecutive days of temperatures at or above 90 degrees F, as compared to non-heat wave days. Why is that? This may be due to housing quality, lack of air conditioning, or lack of transportation to get to cooling centers. Finally, another study out of Penn State found that older women are more at risk for negative health effects from heat waves than older men. The researchers assert that age and biological sex are the most critical factors in predicting whether an adult may be at risk from higher heat and humidity days. To find out more, click here.

For older adults who may have trouble leaving their homes and who are without air conditioning, what can be done to help protect them during heat waves? There is research to support the benefit of using an electric fan and spraying the skin with water during extremely hot and humid days as a way to reduce cardiac stress. However, according to this same research, on extremely hot and dry days, without excess humidity, fan use could potentially have an adverse effect by forcing more hot air into the body. On such days, just wetting the skin was considered more effective. There is also data showing that above 91 degrees F, fans may be ineffective in cooling the bodies of older adults who have trouble cooling themselves down by sweating. So, there is a real quandary as to how to protect our growing aging population at a time of rising temperatures. This will require solutions at the local, state, and federal levels if we are to protect a significant percentage of our population as the ravages of climate change continue.