With the summer’s warm weather settling in, an increasing number of folks are heading outside to enjoy the day exercising or doing other activities. But working and playing outdoors when it’s hot and humid calls for greater precautions than people might be used to if they regularly work out in a climate-controlled gym.
UConn Today recently discussed the dangers of heat illness with Rebecca Stearns, a certified athletic trainer and vice president of operations and director of education for UConn’s Korey Stringer Institute. The Institute promotes the health and safety of professional and recreational athletes at all levels of sport through proper hydration, monitoring, training, and care.
Q: What are the most common heat illnesses that people need to be aware of when they are active in the summer months?
Stearns: The most common heat illness is heat exhaustion. But dehydration, heat cramps, and exertional heat stroke are all possible, with exertional heat stroke being the most severe and life-threatening.
Q: Let’s talk about dehydration first. What are some of the symptoms people might experience when they are seriously dehydrated?
Stearns: Most people will have a strong desire for fluids, dry mouth, headache, they may feel tired or sluggish or start to feel dizzy, and their urine is going to be a dark yellow (like apple juice). Any fluid loss above 2 percent of your body weight will start to affect your ability to stay cool, will increase your heart rate, and will also impair your exercise performance. Once you get into the 4 percent to 5 percent range, strength and power will start to be affected.
Q: What’s the best thing people can do when they are dehydrated and what steps can they take to avoid getting dehydrated in the future?
Stearns: The most important thing to do is get fluids back into your body as soon as possible, by drinking either water or an electrolyte beverage. To avoid dehydration in the future, it’s important to determine why you didn’t have enough hydration to begin with. Most of the time that means knowing your sweat rate, which allows you to calculate how much fluid you should be taking in during exercise. Sweat rate is highly variable between people, as it can range from 1-4 liters of sweat each hour. That’s why it’s important to know your sweat rate, and replace fluids accordingly. Exercising in a warmer environment or for extended periods of time will also cause you to lose more fluids that you are used to, so be prepared when heading into these scenarios.
Q: Let’s talk about heat cramps. We’ve seen this happen to runners and high-performance athletes when a subtle muscle twitch escalates into a painful muscle spasm. What causes cramping and what should folks do when it happens?
Stearns: Muscle cramps could be caused by different factors, but heat cramps are specifically caused by electrolyte loss, usually due to excess sweating in a warmer than normal environment. If you think you are suffering from a heat cramp you should stop exercising, gently stretch the cramp, and try to consume salty foods and fluids. It’s much easier to prevent heat cramps than treat them when they occur, so try to determine what caused your heat cramps to start – it’s usually because of an athlete not being used to exercising in a warm environment, wearing protective equipment in the heat, or exercising for a longer than normal period of time.
Q: Heat exhaustion is a more serious heat-related illness. Can you please explain what heat exhaustion is, and what signs people should watch for if they suspect that someone may be experiencing it?
Stearns: Heat exhaustion occurs when someone is unable to continue to exercise in the heat. This is usually due to an imbalance of the blood within the body. The muscles, skin, and heart all demand blood when exercising in the heat. When exercising intensely, this competition between the body’s systems can cause a person to collapse, essentially allowing the body to catch up with the demands between these systems.
Q: What should you do if you or someone you know is suffering from heat exhaustion?
Stearns: If you believe someone is suffering from heat exhaustion move the person to a cool place, either in the shade or an air-conditioned environment. Have him or her lay down, with their legs propped above their heart, which helps return blood to the heart. Have him or her drink fluids. Placing cold ice towels over the person’s arms and legs can also aid in their recovery. If they do not improve within a few minutes of stopping exercise, seek immediate medical assistance.
Q: Heat stroke is the most serious of the heat-related illnesses. What are the key symptoms of heat stroke, and how is it different from heat exhaustion?
Stearns: Exertional heat stroke occurs when the body’s temperature rises above 104 F, in addition to signs and symptoms of central nervous system dysfunction. Central nervous system dysfunction comprises a wide variety of symptoms, including confusion, combativeness, collapse, altered level of consciousness, and, in severe cases, unconsciousness. Exertional heat stroke occurs when both of these factors are present. Exertional heat stroke is different from heat exhaustion because it has an extremely elevated body temperature, whereas a person with heat exhaustion will have a body temperature below 104 F (usually between 101 F and 103 F). This makes obtaining an accurate body temperature vital for an accurate diagnosis. This is why it is important to also understand that body temperature should be obtained using a rectal thermometer within an exercising individual, as all other devices are inaccurate when a person has been exercising intensely in the heat.
Q: What should you do when you suspect someone is suffering heat stroke, and how can you avoid heat stroke when you’re working, running, or playing in high heat and humidity?
Stearns: If you suspect someone of having exertional heat stroke, call 911. While you wait, you need to aggressively cool the victim. The best method is ice water immersion, where the body is immersed up to the neck with water and ice. If this is not available, douse the person with cold water in a shower or with a hose. The best chance of survival is if the person is cooled on site – given there is appropriate medical care and treatment – within 30 minutes of their collapse. A 100 percent survival rate has been documented when cold water immersion has been implemented within 10 minutes of collapse for an exertional heat stroke victim.
Q: Do you have any general advice for individuals who like to be active in the summer months? Are there certain general precautions folks should heed when venturing outside in the summer?
Stearns: When the summer begins, allow your body time to adjust to the warmer weather. Your body needs 10-14 days to adapt to warmer weather conditions. During this time, your body will change how it reacts to heat so it can better handle exercise in that environment. During these 10-14 days, be sure you are hydrating, taking extra breaks, not pushing your intensity level too high. After you have acclimatized to the heat, you can introduce more intense training. Remember, that if you travel during the summer you may arrive in an area that is warmer than what you are used to and you may need time to adapt. Alternatively, if you vacation in a cooler area and return, you may need to give yourself time to acclimatize again.
In addition, you can try to exercise during the cooler parts of the day, bring water with you, and hydrate appropriately before and after you exercise. Acclimatizing to the weather, hydrating, and adjusting your intensity or providing more breaks on warmer days are some of the top ways you can stay cool in the summer heat.
For more information about heat illness and staying safe, visit the Korey Stringer Institute website.