Heatstroke is a life-threatening emergency. Therapeutic cooling measures need to be undertaken rapidly in order to prevent the catastrophic organ failure associated with markedly elevated body temperature.
The general dictum is to cool the victim to a normal body temperature, but to take care not to go further into the territory of hypothermia (“overshoot”), which theoretically might create another set of difficulties. But perhaps there is an opportunity now for new thinking regarding cooling a heatstroke victim in dire circumstances.
In an article entitled “Successful Treatment of Severe Heatstroke With Therapeutic Hypothermia by a Noninvasive External Cooling System” (Annals of Emergency Medicine 2012;59:491-493), Dr. Jen-Yee Hong and colleagues report treating a near-fatal case of exertional heatstroke using induced therapeutic hypothermia (33oC [91.4o F]) by a noninvasive external cooling system. After treatment, the patient recovered completely, without any neurological sequelae at one year. Prior to cooling, the victim had multi-organ dysfunction, including seizures, lung injury, and coagulopathy (diffuse bleeding).
This is a very important case report, because external cooling devices are much more commonly found these days in emergency departments because they are used to cool patients to protect their brains after they have been resuscitated from cardiac arrest, or in certain other situations where there has been a dangerous period of lack of oxygen to the brain.
The specific device used for this patient was the Medivance Arctic Sun System, which is a noninvasive (no direct access to the bloodstream is obtained) cooling system designed for external temperature management. It circulates chilled water through pads directly adhered to the patient’s skin. While this is a single case report and it is impossible to know if merely cooling the patient from a hyperthermic (hot) condition to a normal body temperature would have been sufficient to achieve the same outcome, it is very important to note that going beyond a normothermic condition to a hypothermic (cold) condition did not appear to be harmful and may very well have been helpful, for theoretical reasons noted by the authors.
Outdoor Ed Note: Thanks Paul for this update. The heat waves happening across the U.S this summer are of particular concern for outdoor programs where physical activity is combined with high heat and humidity. Heat stroke can be an immediately life-threatening illness.
Here are a few other good sources about Exertional Heat Stroke (EHS). One critical observation from a number of these articles is advanced recognition of the problem. The person who is “‘falling behind’ his friends, or collapsing during or shortly after an exercise is suspected to suffer from heat stroke. Staff should be taught to look for these signs and take immediate vigorous steps.
Exertional Heat Illness and Competition – Position Paper by the American College of Sports Medicine (PDF Version)
“Cooling Techniques for Hyperthermia” at Medscape.
Exertional HeatStroke in Israeli Defence Forces (PDF)
Reprinted with permission by the Author from Healthline.com
