Cooling Strategies for Older Adults in the Heat

Overview

The earth's climate is warming, and the number of heat waves has increased in recent years. At the same time, the number of adults over the age of 65 is growing. Humans sweat and increase blood flow to the skin to cool their body when they get hot. Older adults do not do this as well as young adults. This makes it harder to safely be in warm and/or humid conditions. It is important to learn about cooling strategies for older adults to safely be in warm and/or humid conditions. There is compelling evidence that intermittent hand and forearm cold-water immersion effectively reduces the rise of core temperature during heat stress in older adults. However, it is still unknown if this is an effective cooling strategy for older adults. Furthermore, our laboratory has shown that folic acid supplementation improves blood flow responses in older adults. This may be beneficial to older adults during heat stress.

Subjects sign an informed consent form and undergo a medical screening prior to participation. The screening includes a physical exam, anthropometry, chemical and lipid profiles. Subjects participate in 4 experimental trials, 2 while on folic acid supplementation and 2 while on placebo. The order of treatment (folic acid supplementation or placebo) is randomized. Participants will place their hands and forearms in cold tap water intermittently for one of the two trials for each treatment. The order of the hand and forearm immersion trial is randomized for each treatment. The trials are separated by at least five days. For each experiment, core temperature, heart rate, blood pressure, skin temperature, and sweat rate are measured. Each experimental visit will last 2 hours.