Part of the purpose of this page is to try and serve as a source of information to athletes and parents of athletes. One concern for athletes that compete or train in hot weather is dehydration, heat cramps, heat exhaustion, and heat stroke.
- 1. Functions of water in the body.
- a) Regulates body temperature.
b) Maintains blood pressure.
2. Water constitutes 60% of total body weight in males and 50% in females.
Water balance during exercise:
- 1. Acceleration of water loss during exercise is in the form of sweat.
- a) Environmental temperature affects the amount of fluid loss. Humidity levels either inside or outside.
b) Body size.
c) Metabolic rate.
Okay so how to make practical sense of this. There are four common heat disorders that coaches and parents of athletes should be aware of, Heat cramp, heat syncope, heat exhaustion, and heat stroke.
1. Heat cramp: most common in games and activates performed in higher humidity and when the athlete is excessively sweating With a corresponding loss of sodium.
Most common muscles affected are the calf, thigh, or abdominal muscles. Ironicly taking large volumes of water without electrolytes complicates the problem.
Initial treatment for heat cramps:
Stop the activity.
Move athlete to a cool place.
Drink cool saline solutions like Gatorade or sports drink.
Rest, calm and reassure athlete.
If symptoms don’t resolve IV therapy may be needed
2. Heat Syncope: This is when the athlete has a sudden loss of consciousness, typically followed by a strenuous event that has caused maximal Vasodilatation, especially if the athlete is dehydrated. The blood will tend to pool in the extremities, typically the legs and the athlete will become light headed or faint.
Initial treatment for heat syncope
Lay athlete down and elevate legs.
Make sure athlete is hydrated.
The use of proper cool down periods will aid in avoiding this situation.
The next two heat disorders, in my opinion, are very important to know and understand.
3. Heat exhaustion: Is a form of shock, caused by a combination of elevated core body temperature by exercise or exertion in hot weather and fluid depletion.The onset is not necessarily sudden; it can occur over the course a few hours or a few days. Thus athlete doing two a day practices need to be monitored well and have proper cool down and hydration breaks.
One of the easiest ways for an athlete or an athlete’s parent to monitor risk is to use a weight chart to identify if there is a sudden weight loss followed by prolonged periods of fluid loss.
What to look for in heat exhaustio
Rapid shallow breathing
Altered mental state (giddiness to delirium).
Vomiting or nausea.
Tingling in the extremities.
Decreased urinary output.
Initial treatment for heat exhaustion
Same care as for heat cramp.
Remove excess clothing.
Moderate cooling (Using fans and ice).
Move to a cooler environment.
Spray with lukewarm water and cool with a fan.
Observe for shock (athlete should be monitored and closely evaluated for other heat injuries such and heat stroke). If no response, transport for IV therapy. As in all potentially serious injury the athlete should be evaluated before returning to play.
4. Heat stroke: Of the four this is a true medical emergency.
It is important that someone that experiences heat exhaustion does not progress to heat stroke.
Heat stroke is the second leading cause in fatality in football followed by head injuries. Heat stroke is typically associated with a core temperature greater then 104 degrees Fahrenheit. A misconception of heat stroke is that the patient does not sweat, this is untrue. In at least 50% of victims with heat stroke sweating may be present. The factors that lead up to external heat stroke are a combination of external and internal conditions. Externally the humidity, air temperature, and solar radiation play a major roll in athletes developing heat stroke. This is why a humidity reading should be taken before each practices to determine if it is safe for the athletes to engage in strenuous activity. Internal factors such and metabolism and muscle activity regulate how our bodies try to cool our self. If a team chooses to practice in an environment where heat injuries are possible it is suggested that a cooling station be set up with proper cover, fluids and a tub of water with coolers full of ice if sudden decrease in body temperature may be needed. Often some coaches may opt to use the local weather channel to determine if the humidity is safe to practice in. This could be a mistake if the measuring devices used by the weather station, is not within a reasonable distance of the practice location as microclimates can play a roll in local weather patterns.
Symptoms of heat stroke:
Classic heat stroke victims will have hot dry red skin.
Exertional heat stroke victims may be profusely sweating.
Treatment of heat stroke:
Rapid and immediate cooling of the athlete to prevent central nervous system collapse.
Call emergency medical services immediately!
Begin external cooling procedures on site.
Administer oxygen if available.
Remove excess clothing and ice pack armpits, neck, and groin, or ice bath if on site.
If there is uncertainty weather the athlete is suffering from heat exhaustion or heat stroke always assume heat stroke and in either case seek medical assistance.
Remember it is incorrect to assume that the patient’s ability to sweat or not sweat is the primary symptom differentiating heat stroke Vs heat exhaustion.
The longer the delay in getting proper medical care increases the risk of serious injury.
As in all potentially serious injury the athlete should be evaluated before returning to play.
Point of interest:
A reduction in 1% water loss is enough to affect an athlete’s performance.
During a marathon a combination of water loss by respiration and sweat can reduce body water content by 6-10% even with taking fluids through the race.
A water loss ranging from 9% to 12% of total body weight can lead to death.