That’s right! The 90+ degree summer days are upon us. It’s time to start thinking about the best and safest ways to handle the heat.

The Assisting Hands Caretaking Team provides home care in the home and community to assist with errands, enjoyed activities, or exercise. Regardless of where we are providing care, its crucial to limit the risk of heat illness and promote appropriate preventative behavior as we enter the warmer months of the year in the greater Chicagoland area. Our resident intern sheds light on heat illness, why older populations may have greater difficulty with thermal regulations, and steps you or your loved one can take with hotter days approaching.

What is Heat Illness?

Older individuals are at increased risk for heat related illness. Some examples of heat related illnesses include heat cramps, heat exhaustion, and heat stroke:

• Heat cramps are painful muscle spasms that occur in legs, arms, and abdomen. Heat cramps can be reversed with appropriate action such as elevating legs, moving to a cool or air-conditioned environment, and drinking cold fluids that are alcohol and caffeine free.
• Heat exhaustion is the beginning stage of hyperthermia (or increased body temperature) with symptoms including dizziness, heavy sweating, nausea, decreased coordination, and possible rapid pulse. Heat exhaustion can turn into heat stroke if not addressed properly, and heat stroke is a medical emergency.
• Heat Stroke is a progression in hyperthermia with symptoms including behavior change (increased agitation or confusion), poor coordination, weak pulse and fainting or loss of consciousness. Those experiencing heat stroke may also stop sweating all together, especially if they are dehydrating. Heat Stroke is a medical emergency and required immediate professional medical attention.

Why might regulating body temperatures be more difficult with older age?

Thermoregulation is the process of multiple body systems communicating and working together to maintain the internal body temperature at an appropriate 97-99 degrees Fahrenheit. Older adults’ ability to efficiently dissipate heat, which is crucial for thermoregulation in hotter environments, is reduced compared to younger adults. This decreased in efficiency increased the strain put on older adults’ bodies and can increase their risk of having dangerously elevated internal body temperatures or hyperthermia.

There are multiple reasons why older adults are at risk for hyperthermia in warm environments.

First, older adults have changes in their sweat response. Sweat cools the body down as the liquid on the skin evaporates into the air, taking heat along with it. While the number of sweat glands in the skin does not decrease with age, the function of these glands and amount of sweat they are able to be produced decreases. Older adults also have higher core temperature thresholds for simulating sweat production. This means their internal body temperature needs to reach a greater temperature compared to their younger counterparts before triggering an appropriate sweating response. Environmental factors such as humidity can be dangerous and limit the cooling effect of perspiration as the increased water content in the air reduces the ability for sweat to be evaporated.

Secondly, changes in the cardiovascular system as part of natural aging processes or from underlying cardiovascular diseases can impact the body’s ability to dissipate heat through blood flow. Heat is removed from the body by being transferred to the skin from blood and then transferred out into the surrounding air through the sweating evaporation process. More blood needs to be directed towards the skin and skin blood vessels need to be dilation enough for the actual transfer of heat. The capability of both processes (redirecting blood flow and dilating vessels) is reduced in older adults. Without enough blood flow to the skin, heat from the body cannot be removed when sweating begins.

What are some things I can do to handle a heated day?

While you don’t have control over aging processes that make it more difficulty to regulate your body temperature, you do have the ability to change your behavior to limit your risk of heat illness. Such behaviors include keeping your home environment cool with air conditioning units and fans, having shades over windows to block harsh sunlight, and opening windows at night as air temperatures cool. Make sure to also increase fluid intake, specifically fluids without alcohol or caffeine, to stay hydrated. When engaging in physical activity outside, seek shaded areas or walk over natural vegetation rather than paved paths to reduce heat radiation (this is especially important in an urban environment where concrete and asphalt hold a lot of heat). Wear appropriate clothing and have an air-conditioned or cool area in mind to escape the heat if you feel overheated. A cold shower, a wet t-shirt or towel over the neck, or even a slushie are great post-exercise options on a blistering day to cool off.

Did you know? Older adults have a decreased perception of thermal discomfort. This means they may not realize how hot they really are until it’s too late! The sensation of heat discomfort is more likely to drive behavior changes such as drinking more water or pacing yourself appropriately when walking on a hotter day. Even if you don’t feel overheated, it’s still important to use preventative strategies to reduce your risk of heat illness.

What clothing is considered “appropriate” clothing to wear on a hot day?

Good clothes (shirts, shorts, and hats) to wear in the heat depend on the material’s fibers, fit, and moisture wicking technology. Fibers that are thinner, lighter, and less tightly woven will be more breathable. Natural fibers such as cotton are soft, breathable, and durable, but absorb more moisture and can become heavy with sweat. Nylon and polyester are synthetic fibers that are less soft than natural fibers but have great moisture wicking capabilities as they do not hold onto access liquid. For their moisture wicking capability to be maximized, however, they need to be tightly fit with a large amount of skin contact to be fully effective. Finally, many clothes have air ventilation and mesh materials to increase direct air contact to the skin and sweat.

“Hot Weather Safety for Older Adults.” National Institute on Aging, U.S. Department of Health and Human Services, www.nia.nih.gov/health/hot-weather-safety-older-adults.

Knapp, Ken. “How to Pick the Most Breathable Fabrics.” REI, www.rei.com/learn/expert-advice/how-to-pick-the-most-breathable-fabrics.html.

Millyard, Alison, et al. “Impairments to thermoregulation in the elderly during heat exposure events.” Gerontology and Geriatric Medicine 6 (2020): 2333721420932432.