DEHYDRATION AND HEAT ILLNESS

BACKGROUND

Approximately 75% of our body weight comes from water. Most of this water is housed in the cells of our organs and tissues with smaller amounts circulating in our arteries and veins. Our bodies are constantly losing water to the environment through various means including moisture in the air we breathe out, sweating, vomiting, urinating and having bowel movements. The most common way we lose water is through the skin when we sweat. Sweating helps us to cool our skin through the process of evaporation. If we lose fluids faster than we replace them, then we run into a situation of negative fluid balance and become dehydrated. Our body is very good at sensing dehydration. Through various feedback mechanisms, our body’s sensors send messages to other parts of the body to compensate for decreased fluid levels. This is done by shifting fluid remaining in the cells into the blood vessels to increase circulating volume. Also, our heart rate increases and our blood vessels constrict to try and maintain the status quo in the body. Unfortunately, these means of compensation only last a short period of time. Another more effective means of maintaining fluid balance is the thirst mechanism in the brain. This is when the body senses decreased fluid levels and sends a message to our brains telling us to drink. Unfortunately, this mechanism does not work as well in the very young and very old, which increases the risk of these populations suffering dehydration and heat illness. If allowed to progress untreated, dehydration can lead to heat cramps, heat exhaustion or, in some cases, heat stroke which represents a medical emergency that can be fatal if not treated properly and promptly.

WHO’S AT RISK

Those at risk for dehydration or heat illness include:

-Youths and the elderly because of a brain thirst mechanism that doesn’t work as effectively. As a result, these patients tend to develop more significant dehydration before they realize that they are thirsty.

-Those with recent illness or who have had recent vomiting and diarrhea. These populations will tend to have decreased fluid levels because of the recent illness, which increases the risk of heat injury.

-Those with previous heat illness who may have not completely recovered from the most recent episode. Often, those with recent heat illness need about 1-2 weeks to get their fluid levels back to normal. Those that return to activity before their levels are near normal are at increased risk of heat illness.

-Participants in outdoor, midday sports with excessive activity and, in case of all day tournaments, those with decreased rest and recovery time.

-Heavy sweaters are also at increased risk due to their significant loss of fluid and salt from the body

-Those on medications including the following:

-Antihistamines or allergy medications

-Antidepressants

-Seizure medications

-Cardiac/blood pressure medications

-Laxatives

-Diet pills

SYMPTOMS:

Heat Cramps:

-Cramps commonly occur in muscles with heavy activity in a hot environment such as the calves, thighs, abdomen and shoulders

-Athletes may also note dry mouth, nausea or slight dizziness

Heat Exhaustion:

-Progression of previously mentioned heat cramp symptoms accompanied by:

-Heavy sweating

-Weakness

-Confusion

-Dizziness

-Lightheadedness

-Nausea

-Headache

-Increased heart rate

-Dark urine

Heat Stroke:

-Further progression of heat exhaustion symptoms accompanied by:

-Increased body temperature

-Hot, red, flushed skin without sweating

-Rapid pulse

-Shortness of breath

-Abnormal behavior with hallucinations, confusion, agitation or disorientation

-Seizure

-Coma

TREATMENT:

Heat Cramps:

-Discontinue activity and get the individual into a shaded/cooler area

-Gradually rehydrate the athlete with oral fluids such as water/sport drinks, popsicles or jell-o (Do not use sodas, teas or caffeinated beverages as these act as diuretics, which increase urination and further water loss)

-A good way to assess fluid replacement effectiveness is urine output-patients approaching an ideal hydration state put out more and clearer urine

-Stretching out cramped muscles may also be performed

-If an athlete is unable to drink or there is no improvement in symptoms after about 30 minutes, they may need to be transported to a medical facility for IV rehydration

-DO NOT GIVE SALT TABLETS! These can cause stomach upset and address only the salt loss portion of heat illness. Athletes need fluids in addition to salt to correctly treat heat illness

Heat Exhaustion:

-Like with heat cramps have the athlete cease activity, seek shade/air-conditioning and rehydrate gradually with oral fluids

-Remove tight excessive clothing

-Apply cool liquid to the skin in the form of a mist, shower, bath or tub to help cool the body

-Apply ice packs to the back of the neck, groin, armpits and back to help lower body temperature (Packs are placed in these areas because blood vessels are closer to skin which aids in cooling the body faster)

-Call 911 if the athlete:

-Can’t drink

-Becomes increasing confused or lethargic

-Is nauseous/vomiting

-Experiences shortness of breath

-Has continued symptoms for more than 30 minutes

Heat Stroke:

-Dial 911 immediately

-Perform cooling measures mentioned in the heat exhaustion section while waiting for emergency transport

to arrive

PREVENTION OF HEAT ILLNESS/INJURY:

1)Wear light colored, loose fitting clothing

2)Since heat illness/injury is caused by higher temperatures along with fluid and salt loss, drink plenty of water or fluids with electrolytes before, during and after events to maintain adequate hydration

3)Decrease soda and caffeine intake

4)Schedule events for times outside of peak sun and heat intensity (Schedule before 10am and after 6pm if possible)

5)For midday athletic events, try to provide shaded or air-conditioned areas for competitors to cool off

6)Schedule frequent breaks during practice/competition about every 15-20 minutes and encourage fluid intake even if the athletes don’t feel thirsty

7)Individuals who are heavy sweaters may need more salt in their diet (these athletes should consult with a physician before proceeding with this nutritional change)

8)Have competitors use a sunscreen that is SPF 15 or greater to avoid sunburns. Skin that is damaged or burned by the sun cannot produce sweat as effectively and impairs the body’s ability to cool itself

9)After an athlete has suffered a heat illness event, they should be evaluated by a physician to assess whether it is safe to return to play