For many of us, summer is a wonderful time of year—the days are longer, offering more time to spend with family/friends, our moods improve, there are expanded opportunities for exercise, we go on vacation. At the same time, there are health considerations that we do not face during the rest of the year that can interfere with our enjoyment of these activities, if we’re not being careful.
For starters, there is the threat of sunburn and skin cancer, which most people are now aware of. To recap, you should apply a sunscreen with an SPF of 15 or higher 30 minutes before you will be out in the sun. Reapply completely every 2 hours or any time spent in the water. Try to avoid being out during the hottest hours of the day, between 10am and 2pm. Seek out the shade and stay covered when possible—hats, umbrellas, and clothing with an SPF factor are your friends!
Many people notice that they become more fatigued in the summer. This is due to a combination of factors. First of all, your body is working harder to maintain a safe body temperature in the heat. This is done primarily by sweating, which cools the body as it evaporates, and vasodilation, which dilates blood vessels near the skin and diverts more blood to this area to cool it down. Your heart rate and metabolic rate both increase to accomplish these efforts, utilizing more energy than your body normally does. In addition, if you are exercising in the heat, your body is also trying to divert adequate blood to your skeletal muscle to deliver oxygen to the working muscles. Combined with a lower blood volume (from sweating), this puts even more strain on your cardiovascular system. These changes also make exercise more difficult in the summer months, making you feel more fatigued after a workout. For some people, this fatigue can last for hours.
Finally, Exertional and Nonexertional heat illnesses, including Heat Exhaustion and Heat Stroke, are a real threat in the summer months. Heat exhaustion is characterized by the body’s inability to maintain adequate cardiac output (blood flow/delivery), combined with high body temperatures (101-104 degrees) and sometimes, dehydration. This typically manifests by collapse. Heat stroke is more serious, consisting of high body temperatures (>104 degrees) and central nervous system dysfunction, such as seizures or confusion, and multi organ system damage (heart, kidneys, muscle, etc.). This is an immediate medical emergency. The initial treatment for both of these conditions is rapid cooling of body temperature (most important), fluid/electrolyte replacement, and more aggressive medical intervention if needed.
So how do we avoid unpleasant or dangerous outcomes from the heat? Common sense measures, such as those noted above, combined with staying well hydrated (with water, smoothies, juices, and fruits/veggies that replace minerals lost through sweating) are key. Wear loose clothing that is designed to breathe. Limit outdoor workouts to earlier or later in the day, decrease the intensity of your usual workout, and consider shortening your workouts for a couple of weeks in the early summer to give your body time to acclimate to the hotter temperatures (this allows your body to expand blood volume, improve blood flow to the skin, and decrease the threshold at which sweating starts, among other adaptations that help to manage the heat). Be aware of factors that can decrease your heat tolerance and increase the risk of poor outcomes. Those at risk for heat illness include people who have sweat gland dysfunction, those who have viral/bacterial illness, those who use alcohol before/during time in the heat, and those on certain medications that interfere with cardiac function, heat response, or fluid/electrolyte balance. Such medications include blood pressure medications like ACE inhibitors or ARBs, antihistamines/decongestants, stimulant medications, and beta-blockers.