Page 30 - JSOM Summer 2024

The Role of Motivation to
Excel in the Etiology of Exertional Heat Stroke

Kirsten Lalli, MS ; Nisha Charkoudian, PhD ;
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Yonatan Moreh, MD ; David DeGroot, PhD *

ABSTRACT
Exertional heat stroke (EHS) is a medical emergency charac- medical emergency characterized by central nervous system
terized by elevated body temperature and central nervous sys- dysfunction and can include dizziness, confusion, loss of con-
tem dysfunction, and it can include dizziness, confusion and sciousness, organ and tissue damage, and typically but not al-
loss of consciousness, as well as long-term organ and tissue ways body core temperatures of 40°C/104°F or more. If not
1,3
damage. EHS is distinct from classic, or passive, heat stroke promptly treated and properly managed, EHS can be fatal or
and is most commonly observed during intense physical ac- lead to long-term morbidity. 4
tivity in warfighters, athletes, and laborers. EHS is an ongoing
non-combat threat that represents a risk to both the health While the exact prevalence of EHS is likely underestimated,
and readiness of military personnel. Potential risk factors and it is most commonly observed in warfighters, athletes, and la-
their mitigation have been the subject of investigation for de- borers. In fact, EHS is the third leading cause of mortality
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cades. One risk factor that is often mentioned in the literature, in athletes during physical activity. Two studies composed of
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but not well quantified, is that of individual motivation to large data sets that evaluated cases of EHS during 10km road
excel, wherein highly trained military personnel and athletes races reported an incidence between 1.6 and 2.13 per 1,000
exert themselves beyond their physiological limits because of competitors. A systematic review that collated incidences
7,8
a desire to complete tasks and goals. The motivation to ex- of exertional heat illness among military cohorts worldwide,
cel in tasks with high standards of achievement, such as those but did not distinguish cases of EHS specifically, reported in-
within elite military schools, appears to create an environment cidences ranging from 0.2 to 10.5 per 1,000 person-years and
in which a disproportionately high number of exertional heat prevalence of 0.3%–9.3%. In the United States, the Military
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illness casualties occur. Here, we review existing biomedical Health System’s Medical Surveillance Monthly Reports from
literature to provide information about EHS in the context of 2017 to 2021 indicate that Fort Benning (now Fort Moore)
motivation as a risk factor and then discuss five cases of EHS usually has the highest frequency of heat casualties of all De-
treated at Martin Army Community Hospital at Fort Moore, partment of Defense posts in the U.S., with 1,911 total heat
GA, from 2020 to 2022. In our discussion of the cases, we casualties treated at Martin Army Community Hospital, 349
explore the influence of motivation on each occurrence. The of which were EHS, including one fatality due to EHS. 10–13 The
findings from this case series provide further evidence of moti- high frequency of EHS at Fort Moore results from the combi-
vation to excel as a risk factor for EHS and highlight the need nation of individual medical risk factors and mission-related
for creative strategies to mitigate this risk. risk factors, as most of those casualties occur during Ranger
and Infantry training.
Keywords: heat stress; behavioral thermoregulation; human;
military personnel; motivation; heat stroke EHS is an occupational hazard that threatens both the health
and readiness of military personnel, particularly when person-
nel perform strenuous physical activities for extended periods
of time in hot environments. EHS sequelae not only affect the
Introduction
morbidity and mortality of individual service members, but
Exertional heat illnesses represent a spectrum of medical con- also negatively impact force readiness as a whole. 14,15 Accord-
ditions that can affect physically active or exercising individ- ingly, risk factors and their mitigation have been the subject
uals in both hot and cool environments. The milder forms of of investigation for decades. 9,16–20 Minard’s paradigm divides
exertional heat illnesses are exercise-associated muscle cramps EHS predisposing factors into three groups: individual phys-
and heat exhaustion, while the most severe is exertional heat iologic limiting factors, environmental factors, and training
stroke (EHS). EHS is the most serious form of heat illness organization factors. Physiologic factors include existing or
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1,2
and is distinct from classic heat stroke in that it arises from recent viral illness, inadequate physical fitness, lack of accli-
strenuous physical activity instead of from passive exposure matization to the environment, and sleep deprivation. Envi-
to environmental heat, such as during heatwaves. EHS is a ronmental factors refer to the heat load at the location of the
1
*Correspondence to LTC David DeGroot, Director, The Army Heat Center, Martin Army Community Hospital, 6600 Van Aalst Blvd., Fort
Moore, GA 31905 or david.w.degroot.mil@health.mil
1 Kirsten Lalli is a medical student at the Yale University School of Medicine, New Haven, CT. Dr. Nisha Charkoudian is the Chief of the Thermal
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and Mountain Medicine Division at the US Army Research Institute of Environmental Medicine, Natick, MA. CPT Yonatan Moreh is a Resident
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Physician with the Department of Family Medicine, Martin Army Community Hospital, Fort Moore, GA. LTC David DeGroot is Director of
The Army Heat Center, Martin Army Community Hospital, Fort Moore, GA.
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