My bout of hyperthermia on last year’s Chicago Mac was something I never experienced
before. I’m active, in good shape and know how to hydrate since I’m an avid cyclist. For me
hydration wasn’t the issue. I spent too much time in the sun without a hat and covered up
too much at night due to the biting flies. My core temperature peaked AFTER the race on
the delivery trip back to Chicago. I got to the point where I couldn’t think clearly so I
handed the boat over to another for the return trip. It took 2 days and a cold hotel room
before I felt normal again. I had no idea what I was experiencing until after the event.
That’s why I wrote the article. No one should ever have to experience hyperthermia armed
with a little knowledge and preparation.
Definition – Hyperthermia is elevated body temperature due to failed thermoregulation that
occurs when a body produces or absorbs more heat than it dissipates. Extreme temperature
elevation then becomes a medical emergency requiring immediate treatment to prevent
disability or death. The most common causes include heat stroke and adverse reactions to
drugs (such as antihistamines and diuretics http://en.wikipedia.org/wiki/Hyperthermia –
cite_note-Harrisons-8). The former is an acute temperature elevation caused by exposure to
excessive heat, or combination of heat and humidity, that overwhelms the heat-regulating
Signs & Symptoms – Hyperthermia is defined as a temperature greater than 99.5–100.9 °F.
Body temperatures above 104 °F can be life-threatening. Other symptoms include muscle
cramps, fatigue, dizziness, headache, nausea, vomiting, and weakness. The heart rate may
be elevated, and the skin is reddened. The skin may be moist if sweating is still occurring,
or it may be dry if sweating has stopped. Confusion and mental changes may develop, and
seizures can occur with brain damage. In severe heat stroke the person may be confused,
hostile, or exhibit seemingly intoxicated behavior. Heart rate and respiration rate will
increase as blood pressure drops and the heart attempts to maintain adequate circulation.
The decrease in blood pressure can then cause blood vessels to contract resulting in a pale
or bluish skin color in advanced cases. Eventually, organ failure, unconsciousness and death
Treatment – Treatment for heat exhaustion includes recognizing the symptoms, stopping the
activity, and moving to a cooler environment. Rehydration with water or a sports drink is the
cornerstone of treatment for heat exhaustion. Move out of the sun. Make sure the person is
adequately hydrated. Keep water on the head using a soaked cloth or wetted sweat band.
Rest in a cool place. Remove excess clothing. Cool the person with air movement and water mist. Active cooling methods, such as sponging the head, neck, and trunk with cool water,
remove heat from the body and thereby speed the body’s return to normal temperatures. If
symptoms get worse, apply ice or cold compresses to the neck, armpits and groin. Immerse
in tepid or cool water if the condition is extreme.
Hyperthermia that results from drug exposure requires prompt cessation of that drug, and
occasionally the use of other drugs as counter measures. Fever-reducing drugs such as
acetaminophen and aspirin have value in treating hyperthermia. Always consult with a
physician before cessation or administration of drugs.
When the body temperature reaches about 104 °F, or if the affected person is unconscious
or showing signs of confusion, hyperthermia is considered a medical emergency that
requires treatment in a proper medical facility.
Prevention – Stay adequately hydrated with cool water combined with an electrolyte
balancing drink. Avoid drinks containing caffeine, alcohol, or large amounts of sugar and
energy drinks because they will actually cause you to lose more fluid. Avoid hot, heavy
meals. Avoid direct exposure to the sun. Wear a vented wide brimmed hat, a sweat band
and cooling cloth over the neck. Wear lightweight, light-colored, loose-fitting clothing. Wear
sunscreen to protect skin from the sun’s harmful rays. Sunburn affects your body’s ability to
cool itself and causes a loss of body fluids. Use mosquito netting or a light sheet when
sleeping with biting flies.
Original article post: http://www.cycracetomackinac.com/assets/1/7/July_2_Safety_Thursday.pdf