Emerging Extreme Heat Patterns and the Elderly

"Older adults are one of the populations that we classically see as being more vulnerable to the effects of climate change, specifically to the effects of extreme heat."

"As we age, our ability to adapt to heat diminishes."

"Medications can amplify some of those heat effects."

Catharine Giudice, emergency physician, climate change and human health fellow, FXB Center, Harvard 

Source: National Climate Assessment

 

Climate change is real; global average temperatures have reached 1.2C above pre-industrial levels. We have experienced heat waves that are more frequent, more intense than just a few decades earlier. Excessive heat has seen school closures, led power grids to their limits, and taken vulnerable lives around the world. Even as the planet continues to warm, global humanity itself is aging. There were 1.2 billion people 60 years of age and older in 2021 and by 2050 it is estimated that number will increase by another billion, leaving older adults exposed to levels of heat more dangerous than at present.

In June of 2020, a heat dome struck across the Western U.S. and Canada with fatalities resulting that exposed a troubling pattern leading to the realization of the extreme vulnerability of the aged. In Oregon, 56 of the 72 people who perished of heat were aged 60 and up, while in British Columbia, those 60-plus accounted for 555 of 619 fatalities due to the crushing heat. In England a year later, June, July and August saw 2,800 deaths among those 65 and older due to sizzling heat.

The human body, confronted by rising temperature, is geared toward thermoregulating to avoid overheating. Sweat releases heat when it evaporates. "Older people don't sweat as much", states Deborah Carr, professor of sociology, Boston University, whose study is aging. "They have essentially a less efficient cooling system. So they're in extreme heat and don't sweat it out", she explained.

Increased blood circulation is another cooling body response to heat, drawing heat from deep within to the skin. "The heart has to sometimes pump two to four times more blood each minute than it would on a cooler day", explains Renee Salas, with the Center for Climate, Health and the Global Environment at T.H. Chan School of Public Health, Harvard. Although a healthy heart handles the pumping, people with heart disease and allied cardiovascular issues struggle to.

Medications treating  chronic health conditions such a diabetes, hypertension and lung issues which can inhibit the body's capability to respond to heat, also impair that response, by decreasing the ability to sweat or through increasing the need to urinate, which can result in dehydration. Research shows that by the time an elderly person feels acute discomfort as a result of high temperatures, their body may already be suffering.

Many elderly people don't rehydrate as often as they should and may also be on dehydrating medications, which could contribute to their higher risk of serious illness or death during heat waves. (Eric Gaillard/Reuters)

"Many susceptible people may not recognize when they are overheating, but another person can help identify a risky situation with some careful questions and observations."

"Check in as often as possible. At least twice a day and once in the evening when it is hottest indoors."

Sarah Henderson, scientific director, Environmental Health Services, B.C Centre for Disease Control