Dehydration, Heat Exhaustion and Heat Stroke
Tips for training and playing in the heat and avoiding dehydration, heat exhaustion and heat stroke.
by Brad Walker | First Published July 18, 2002 | Updated August 9, 2020
Although heat injuries are one of the most common forms of sports injuries to effect athletes, they are totally preventable.
Heat injuries and illness occur when your body temperature rises above normal, or when your body is no longer able to regulate heat loss. Heat injuries are generally defined in three stages.
3 Stages of Heat Injuries / Illness
- Dehydration (sometimes referred to as hypohydration): This is the first stage of a heat injury. It’s the mildest form of heat injury in which your body simply suffers from a lack of fluid. Wikipedia defines dehydration as, a deficit of total body water, with an accompanying disruption of metabolic processes.
- Heat Exhaustion: This is the next step beyond dehydration. If not treated immediately, serious injury and even death can result. Wikipedia defines heat exhaustion as, a severe form of heat illness. It is a medical emergency. Heat exhaustion is caused by the loss of water and electrolytes through sweating.
- Heat Stroke: This is the worst stage of a heat injury. Without proper medical attention a victim can die within minutes. Wikipedia defines heat stroke as, a type of severe heat illness that results in a body temperature greater than 40.0 °C (104.0 °F) and confusion.
What Causes Heat Injuries / Illness?
There are several contributing factors that increase your chances of suffering a heat injury. Some of them are obvious, like high temperatures, others are less obvious. To follow is a list of factors to be aware of when training, playing or working in the heat:
- High temperatures;
- High humidity;
- Sun exposure;
- Excessive activity and exertion;
- Coffee and alcohol;
- Medications, especially diuretics; and
- Illness, especially vomiting and diarrhea.
What are the Signs and Symptoms?
There are plenty of warning signs that will notify you, and others around you, that dehydration in setting in. The major problem with the following signs and symptoms is that most people tend to ignore them until it’s too late. Catch these signs early enough and you won’t have any problems, but ignore them, and you’ll pay dearly.
The following signs and symptoms have been arranged to begin with the mildest warning signs first. By the time you start suffering from the signs halfway down the list, you’re in big trouble. Remember; catch heat injuries early by looking out for the warning signs at the top of the list.
- Weak, no energy
- Hot, dry skin
- Weak, but rapid heart rate
- Low blood pressure
- Rapid breathing
Drink Water Till You Pee Clear!
There is one other sign that is often overlooked, and I feel it’s one of the best indicators of your level of hydration. It’s simple to check and very reliable as an indicator of possible dehydration and heat illness.
The color of your urine will tell you a great deal about your body’s level of hydration. When your body is depleted of fluid and dehydrated, your urine becomes very dark in color. In severe cases it can be a dark brown color. However, when your body is fully hydrated, your urine is a noticeably light color, even clear.
My recommendation: drink water till you pee clear. This way you’ll always know that your body is fully hydrated.
How do you Prevent Heat Injuries?
As with all sports injuries, it’s far better to prevent them from occurring, than to treat them after it becomes too late. Prevention is even more important with heat injuries, because if you leave it too late, you may not get a second chance. To follow is a list of things you can do, to prevent heat injuries.
- Drink, and drink often. Before, during and after any training or competing. Don’t wait to become thirsty. Remember drink fluid until you pee clear. Water is usually best; however, a good quality sports drink will also help to replace salts and minerals lost through sweat.
- In Australia, they have a saying called; “Slip, Slop, Slap!” Slip on a shirt, Slop on some sunscreen, and Slap on a hat. It’s good advice whenever you go out in the sun.
- Wear loose fitting clothing that doesn’t restrict your movement, and also allows for a good circulation of air.
- Avoid the extreme heat of the middle of the day. If possible, schedule your training and playing times around the cooler parts of the day. Maybe even opt for a workout in the pool instead of the running track.
- Avoid sunburn at all costs. Sunburn will draw fluid from other areas of your body to replenish moisture in the skin. Remember, Slip, Slop, Slap.
- Schedule plenty of rest time in cool, shaded areas, as part of your training and playing.
- If possible, acclimatize to your current training and playing environment.
- Avoid caffeine, alcohol and sugary drinks like soda, cola and fizzy drinks.
- Lastly, use a bit common sense and don’t ignore the warning signs.
How do you Treat Heat Injuries?
Generally speaking, the treatment for dehydration, heat exhaustion and heat stroke are very similar. However, whenever dealing with a victim of heat stroke, the patient must be referred to professional medical assistance. Remember, heat stroke is life threatening, don’t take any chances, call for professional medical help.
To follow are a few guidelines for treating heat injuries.
- Have the patient lie or sit down in a cool, shaded area with good air circulation.
- Elevate the feet.
- Loosen any clothing.
- Start to replace both fluid and salt loss. Give both water and sports drink if available.
- Saturate clothing in cool water. If necessary, remove outer clothing and wrap patient in a wet sheet or towel.
- Use fans or other cooling devices to help reduce body temperature.
- Immerse in cool (not cold) water. (Bath, swimming pool, river, lake, etc.)
Remember; if the patient is suffering from any of the serious warning signs like confusion, a weak, rapid pulse or becomes unconscious, seek medical help immediately.
Dehydration, Stretching and Flexibility
As water makes up approximately 75% of muscle mass, it’s no surprise that dehydration can have a negative effect on muscle stiffness and flexibility. Good hydration helps to improve collagen elasticity and muscle function, and is very important when trying to enhance flexibility.
Research has shown that increasing hydration causes an increase in lubrication and separation within the extracellular matrix (ECM), which assists in both initial and long-term flexibility gains.
Research and References
- Bahr, R. Maehlum, S. (2004) Clinical Guide to Sports Injuries, 1st Edition (ISBN: 978-0736041171)
- Martini, F. Tallitsch, R. Nath, J. (2009) Human Anatomy, 9th Edition (ISBN: 978-013432076X)
- Nuccio, R. Barnes, K. Carter, J. Baker, L. (2017). Fluid Balance in Team Sport Athletes and the Effect of Hypohydration on Cognitive, Technical, and Physical Performance. Sports Medicine, 47(10): 1951–1982.
- Popkin, B. D’Anci, K. Rosenberg, I. (2010). Water, Hydration and Health. Nutrition Reviews, 68(8): 439–458.
- Riebl, S. Davy, B. (2013). The Hydration Equation: Update on Water Balance and Cognitive Performance. ACSMs Health and Fitness Journal, 17(6): 21–28.
- Tortora, G. Derrickson, B. (2009) Principles of Anatomy and Physiology, 14th Edition (ISBN: 978-1118866096)
- Ullucci, P. Casa, D. Matthews, T. Rosene, J. (2017) Dehydration Reduces Posterior Leg and Trunk Flexibility and Increases Stiffness in Male Collegiate Age Runners. European Journal of Sports & Exercise Science, Volume 5, Issue 2.
- Walker, B. (2018). The Anatomy of Sports Injuries, 2nd Edition (ISBN: 978-1623172831)
- Wikipedia contributors. (2020, June 15). Dehydration, In Wikipedia, The Free Encyclopedia.
- Wikipedia contributors. (2019, November 27). Heat exhaustion, In Wikipedia, The Free Encyclopedia.
- Wikipedia contributors. (2019, July 19). Heat stroke, In Wikipedia, The Free Encyclopedia.
About the Author: Brad Walker is often referred to as the "Stretch Coach" and has even been called the Stretching Guru. Magazines such as Runners World, Bicycling, Triathlete, Swimming & Fitness, and Triathlon Sports have all featured his work. Amazon (author page) has listed his books on five Best-Seller lists. Google cites over 100,000 references to him and his work on the internet. And satisfied customers from 122 countries have sent 1,000's of verified customer reviews. If you want to know about stretching, flexibility or sports injury management, Brad Walker is the go-to-guy.
Disclaimer: The health and fitness information presented on this website is intended as an educational resource and is not intended as a substitute for proper medical advice. Please consult your physician or physical therapist before performing any of the exercises described on this website, particularly if you are pregnant, elderly or have any chronic or recurring muscle or joint pain.