Heat related pathologies are a group of disorders, associated with impairments of thermoregulation, which occur while individuals are exposed to high temperatures. The spectrum of these clinical entities ranges from syndromes with mild/moderate clinical manifestations, like heat edema/cramps/rash to the life-threatening heat stroke.

1. Heat related disorders
Dr. Enida Xhaferi1
, Dr. Altina Xhaferi2
, Dr. Esmeralda Thoma1
, Msc Miranda Cela1
, Dr.
Fatbardha Lamaj3
1
University of Medicine/Faculty of Medical Technical Sciences, Tirana, Albania
2
Hygeia Hospital, Tirana, Albania
3
Intermedica Laboratory, Tirana, Albania
Heat related pathologies are a group of disorders, associated with impairments of
thermoregulation, which occur while individuals are exposed to high temperatures. The
spectrum of these clinical entities ranges from syndromes with mild/moderate clinical
manifestations, like heat edema/cramps/rash to the life-threatening heat stroke.
Heat accumulates in the body, when environmental exposure and metabolic needs are not
properly balanced by heat dissipating mechanisms. Factors that increase the risk of developing
heat related disorders include: presence of underlying medical conditions (like cardiovascular,
dermatologic, pulmonary diseases) use of medications, improper acclimatization, exposure to
very high temperatures/humidity, engaging outdoors in demanding exercise/work, lack of
physical fitness, wearing excessive clothing. Management of mild disorders is mainly
supportive, and associated adverse events occur rarely.
Heat stroke, on the other hand is a medical emergency, characterized by hyperthermia (rectal
core temperature ≥ 40°C) and central nervous dysfunction. The ensuing multiorgan injury and
hazardous complications, necessitate prompt diagnosis and thorough management. Rapid
cooling is the cornerstone of therapy. Techniques include cold water submersion, evaporative
cooling, complete body ice packing/local ice packing and application of invasive cooling
measures. Patients should be hospitalized and monitored carefully.
This short review aims to present the clinical manifestations and management of heat related
diseases. Despite all current medical advances, prevention remains the safest, most cost-
effective intervention for reducing incidence, morbidity and mortality, associated with these
pathologies.
Background. Humans are susceptible to high temperatures and heat stress. According to CDC,
in the USA, there have been 7046 deaths, attributable to excessive heat exposure, for the time
period between 1979 and 1997.
Heat is toxic to cells. Very high cellular temperatures lead to injury, disruption of cellular
pathways and biochemical reactions, denaturation of proteins and ultimate cell death. Heat
stress is associated with the release of inflammatory cytokines, interleukins and heat shock
proteins.
Acclimation (or acclimatization) to heat, involves a series of physiological adaptations, gained
during repeated exposure to high temperatures, which improve cardiovascular performance and
enhance other body heat coping mechanisms (increase capacity to produce sweat, improve salt
conservation by kidneys and sweat glands, boost activation of the renin–angiotensin–
aldosterone system, increase in glomerular filtration rate etc.).

2. Temperature regulation is negatively affected by hypothalamic dysfunction. Some other factors
which can interfere and reduce the efficacy of body’s heat elimination mechanisms include:
cardiovascular disorders, skin pathologies, high air temperatures/ ambient humidity, use of
some medicines, reduced ability for acclimatization, inadequate behavioral responses.
Heat related illnesses, are disorders resulting from the stress of responding to an excessive
thermal burden, where the body is unable to cope effectively with heat. Dysfunctional
thermoregulation derives from the inability to eliminate heat adequately. Heat illnesses
encompass a spectrum of conditions, varying form minor entities like heat edema/cramps/rash
to heat exhaustion/ syncope and the very hazardous life-threatening heat stroke.
There are two types of heat stroke: exertional heat illness (EHS) which affects primarily young
persons, mainly athletes, military personnel, outdoor workers and the classic, non-exertional
heat stroke (NEHS), involving elderly, sedentary individuals or the chronically ill. EHS is not
necessarily linked with heat waves (defined as a weather phenomenon, during which, for a
period of three or more days, the maximum shade temperature is ≥32.2°C) and is the leading
causes of death in young athletes each year. These two clinical entities have common clinical
manifestations, but are caused by differing underlying pathological mechanisms. Exertional
heat stroke occurs mainly when body’s heat elimination mechanisms are overwhelmed by
endogenous excessive heat production.
Objective. Present briefly the most common heat related illnesses and measures that should
be taken to manage them effectively and prevent future occurrences.
Methods. A literature review was conducted. Pathophysiology, clinical manifestations,
recommended therapeutic interventions were analyzed, organized and summarized below.
Results. In general, heat related disorders are due to the following factors: surplus heat
exposure from environment; an incompetence of the body’s cooling mechanisms to eliminate
heat or a combination of these two variables.
Heat edema involves a temporary swelling of the extremities (feet, ankle, hands), some few
days after heat exposure. Lower extremities are typically affected, but fluid can accumulate in
any other body’s dependent area. Peripheral vasodilation, venous stasis and increased water
retention from secondary aldosterone secretion are the main components of this benign
condition’s pathology, which occurs in poorly acclimatized individuals, exposed to high
temperatures. It is important to exclude other systemic causes of edema. Heat edema requires
no specific treatment and the disorder will resolve spontaneously after acclimatization.
Elevation of extremities helps.
Heat cramps are painful involuntary spasms of the heavily worked, large muscle groups, which
are used during exertion. They are the result of electrolytes’ loss in sweating (a very important
heat dissipation mechanism). Heat cramps are short lived, involve specific muscles and almost
never cause rhabdomyolisis. Management includes fluid and salt replacement, massage, stretch
and rest in cool environment. Drinking electrolyte beverages and maintaining adequate dietary
salt intake helps prevent their occurrence.
Heat rash is a maculopapular rash, characterized by inflammation and blockage of sweat ducts,
affecting both children and adults. Sweat ducts may become dilated and rupture into the dermis,
developing thus, consecutive dermatitis or a secondary bacterial infection. Use of loose-fitting

3. clothes is recommended and chlorhexidine cream or salic acid cleaning of lesions, might be
useful. Antibiotics should be applied when infection develops.
Heat syncope occurs usually after exercising and is due to postural hypotension, resulting from
volume depletion, peripheral vasodilation, and decreased vasomotor tone. Patients should be
evaluated for injuries that may have resulted from the falls that accompany usully syncopal
episodes. Treatment involves cooling and oral or intravenous rehydration.
Heat exhaustion is the most common heat related illness, marked by excessive dehydration,
electrolyte depletion, and decreased cardiac output. Patient’s mental status remains intact and
his core body temperature rarely exceeds 40°C. Common symptoms include headaches,
tachycardia, malaise nausea, dizziness. Treatment consists of cooling, oral or intravenous
rehydration.
Individuals with heat exhaustion should be evaluated and managed in the emergency
department, where laboratory studies (comprising - complete blood count, coagulation studies,
urinalysis, basic metabolic panel, liver function tests) should be carried out and vital signs
monitored.
Heat stroke is the most severe form of heat related disorders. Both types - classic and exertional
heat stroke, are characterized by core body temperature > 40 °C and neurologic abnormalities
(irritability, confusion, delirium, inappropriate behavior, seizures). Other symptoms that
patients might have include: anhidrosis or excessive sweating, tachycardia, tachypnea,
hypotension.
Heat stroke occurs when heat load is not modulated properly. Pathophysiology is complex, and
the combination of severe physiological alterations and biochemical reactions contribute to the
creation of the systemic inflammatory response syndrome (SISR; similar to septic shock),
which might cause rapid deterioration of patient’s clinical situation, multiorgan failure and
subsequent death.
Heat stroke treatment should be carried out on site and in the emergency department. Patient’s
airway, breathing, and circulation should be maintained, and cooling, which is the cornerstone
of therapy, should ensue rapidly. Cooling techniques include - cooling by evaporation,
immersion cooling, applying ice packs, invasive cooling measures and other cooling methods.
It is important to apply resuscitation measures, monitor patient’s situation and manage
complications promptly.
Conclusions. Heat disorders comprise a group with both mild and severe illnesses. There are
many factors, which can disrupt body’s heat elimination mechanisms (like cardiac conditions,
taking certain medications/diuretic therapy, anihidrosis) and increase the risk for development
of heat illnesses. Heat stroke is a very hazardous condition. It is important that individuals take
immediate action when they feel uncomfortable heat and avoid risks underestimation.
Some important interventions which could help avoid serious, future illnesses include: being
aware of personal/environmental risk factors, applying acclimation protocols for personnel that
works/exercises outdoors, avoiding strenuous exercise, as indicated by the heat index chart
guidelines, drinking plenty of fluids and avoiding alcohol, wearing light and loose fitting
clothes, taking advantage of shaded/air conditioned areas. Medicine is advancing but for this
entity like for the many other medical disorders, prevention is just better than the cure.

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Bibliography
Enida Xhaferi has finished Medical School at the Faculty of Medicine, University of Tirana, in July 2002
and completed Clinical Rheumatology residency in Tirana, in March 2007. She has been working for the
University of Medicine of Albania since 2010, where she teaches Internal Medicine and Management of
Patients during Disasters.