to the editor: I would like to point out an area of concern with the algorithm presented in Figure 1 of this article. The algorithm seems to suggest that patients with central nervous system symptoms who have a rectal temperature less than 104°F (40°C) do not require immediate evaluation and treatment for heat-related illness. I think this may mislead the reader to think that a lower temperature rules out heat stroke and a need for urgent treatment. Although that may be true by definition, I think the next step clinically should include much more than simply considering alternatives as suggested by the algorithm. Certainly, that would be the case in an acute exercise-related condition or any time a patient has an elevated temperature and central nervous system symptoms. Therefore, I would expect the algorithm to include at least an arrow pointing from this section to the “Treat for mild heat-related illness: Observe for symptom resolution/ Monitor core temperature” section or to the box containing more urgent care for heat stroke.

Athletic protocols¹ and my understanding of the literature² suggest immediate initiation of treatment for suspected heat-related illness (even before the temperature is obtained), and not delaying that treatment while investigating other causes.

in reply: Dr. Helming's point regarding Figure 1 is a valid one. For those with central nervous system symptoms, but a rectal temperature less than 104°F, the diagnosis of heat-related illness should certainly be considered. This would be especially true for a primarily healthy person engaged in physical activity. The article reviewed the management of heat-related illness in all patient populations; therefore, the primary point of that portion of the algorithm was that the presence of central nervous system symptoms, but not hyperthermia, warrants a consideration of alternative diagnoses.

Two other points in Dr. Helming's letter also warrant responses. First, the algorithm does not imply that the presence of central nervous system symptoms and the absence of a rectal temperature of 104°F should result in any less need for urgent treatment. Heat-related illness and the alternatives listed in Figure 1 are all potential medical emergencies. Second, Dr. Helming states that treatment for heat-related illness should be initiated before obtaining a rectal temperature. One of the key points of the article was that a measure of core temperature is needed to accurately diagnose the patient. This point applies to all populations, but is especially true in older patients and those with comorbidities.