Field Health Beat: Hyperthermia

By Mary Gouchnour Hudson

ARPP field crew are often subjected to extreme environmental conditions during field operations. Wide fluc-tuations between hot and cold temperatures can be exacerbated by brutal humidity, wind, and rain. In addition to exposure to these factors, field crew endure long hours of heavy, physical exertion either in the elements on the screendeck, or underwater for two-hour long-and-hard dive rotations. When not working the screen or diving, those remaining topside are engaged in other, sometimes strenuous activities vital to the project. No shelter is readily available, and operations are suspended only for storms accompanied by lightning, hail, or high winds. (We actually enjoy this.)

It is extremely important that field crew understand the nature of sudden illness caused by exposure to the above environmental conditions. Knowing what to do and what not to do in case of emergency will aid in the successful recovery of a victim, and prevent further injury or even death.

The normal temperature of the human body is 98.6 degrees Fahrenheit (F). Using complicated mechanisms, the body normally regulates and maintains this temperature, regardless of the temperature of the environment. Illness results when these regulating mechanisms are overwhelmed.

The following is Part One of a two part series. Part Two (addressing Cold Exposure) will appear in the 1999 issue of the Aucilla River Times.

Heat Exposure

Sweating, evaporation of sweat, and dilation of surface blood vessels allow the body to rid itself of excess heat. Since sweating depletes the body of fluids and electrolytes (salts), it is important to maintain adequate fluid levels by drinking at least 8 ounces of water or electrolyte beverage (i.e. Gatorade, etc.) about every 30 minutes. Do not take salt tablets. Also, wearing either clothing that breathes, like cotton, or wearing layers of clothing that can be peeled off allows for proper evaporation of sweat. Humidity interferes with evaporation, so excessive sweating can be a problem, especially when wearing layers. Wearing a full wetsuit is great for insulation against the cold or underwater; however, that same insulation prevents heat from escaping and prevents sweat from evaporating. Everyone should keep an eye on the safety diver who stays fully suited up when itís hot. Keep a watch on crew who push themselves too hard without adequate rest (you know who you are!). Last, but not least, we should all watch each other, remember to take occasional breaks, and hydrate, hydrate, hydrate!

When sudden illness does occur, it takes one of three forms : heat cramps, heat exhaustion, or heat stroke. Heat cramps present as painful muscle spasms in the extremities during or just after vigorous exercise. To treat, move the victim to a shaded, cooler area, rest the cramps by having him/her lie down, and give water or Gatorade like beverage. Heat exhaustion presents with the following signs and symptoms: cold and clammy skin, gray face, dizziness or weakness, nausea, headache, sometimes a rapid pulse, and usually normal to slightly elevated temperature. High temps around 104 degrees are serious, and imply the victim may be progressing towards heat stroke (watch carefully). To treat, immediately move the victim to a shaded, cooler area, loosen clothing, remove excess layers, and urge him/her to lie down. Give water or Gatorade only if the victim is fully alert (up to a liter if possible). If symptoms do not clear within about 30 minutes, the victimís level of consciousness decreases, or the temperature remains elevated or continues to rise, the victim should be transported to the hospital promptly, for proper monitoring and IV fluid therapy. Heat Stroke is a life threatening illness which, if left untreated, will always result in death. Victims present with hot, dry, flushed skin, although some heat exhaustion victims who progress to heat stroke may still retain some moisture (sweaty clammy skin). Sweating does not occur because the sweating mechanism has been overwhelmed. As the body temp rises rapidly (up to 106 degrees), the level of consciousness decreases to an unresponsive state. The pulse progressively becomes weaker, and the blood pressure falls rapidly. Recovery depends on the speed and vigor of treatment. The senior most qualified medical crew member will decide whether to call 911, activate helicopter transport, or proceed by surface evacuation immediately to the nearest medical facility. In the meantime, in the field, the victim must be cooled by any means necessary. Remove clothing, place wet towels, etc., on the victim, even place ice packs in the groin areas, arm pits, neck and wrists. The hospital, by receiving prior notice, can have ice water baths and other medical interventions available for immediate treatment. Remember, heat stroke, left untreated, will always result in death, and time is of the essence!

The ARPPís commitment to safety through education, policy, and procedure enforcement continues to provide staff, volunteers, and visitors with the best security possible in a potentially hazardous environment. Good science, combined with dedication to safety first, allows us all to experience and enjoy the wonders of the Aucilla River.