YOU`RE SO HOT! SUMMER BRINGS HEAT

YOU’RE SO HOT! SUMMER BRINGS HEAT-RELATED PROBLEMS
JAY BUNTEMEYER, EMS educator,
Porter, Littleton and Parker Adventist
Hospitals
Colorado’s average summer temperature
is 82°F (27.7°C). This summer has been
particularly warm, and EMS personnel
have undoubtedly seen a number of
heat-related emergencies.
Heat transfer happens in several different
ways. Conduction is a form of heat transfer by direct physical contact. Convection
is the transfer of heat into the surrounding atmosphere by the wind; increased
winds can mean increased heat loss.
Radiation is a major source of heat loss
and occurs from electromagnetic waves.
And evaporation is a mode of cooling the
body; problems can arise when a patient
no longer has the ability to sweat.
The body has three systems that work
symbiotically to maintain homeostasis.
The body’s thermosensors are neurons
located in the skin, muscles and spinal
cord. The central integrative area interprets the signals from the thermosensors
and helps regulate the thermoregulatory effectors to maintain a specific body
temperature by affecting skin blood flow
(vasoconstriction or vasodilation) and
sweating. Any deficiency or failure of one
of these systems can quickly result in a
hyperthermic state.
One of the first signs of heat-related
problems is heat cramping. Heat cramps
are a byproduct of replacing lost fluid
(isotonic) with water (a hypotonic solution), thus creating salt loss followed by
muscle fatigue and spasms or cramping.
Treatment includes stopping exertion and
replacing fluids with a sodium replacement substance such as saline.
Failure to pay attention to heat cramps
can lead to heat exhaustion, the result
of both water and salt depletion. Heat
exhaustion presents with malaise, weakness, fatigue, headache, nausea, vomiting
and tachycardia. The core temperature is
generally below 104°F (40°C). Treatment
consists of moving the patient to a cooler
location and replacing volume orally or
intravenously.
Heat stroke is the final step before a
patient ultimately succumbs. Generally,
heat stroke results in core temperatures
in excess of 104.9°F (40.5°C). A defining
feature is neurologic dysfunction (i.e.,
altered mental status) with subsequent
cardiovascular, hepatic and/or gastrointestinal dysfunction or failure.
Heatstroke presents in two ways.
Exertional heatstroke is common in
younger or more active people such as
athletes, military recruits and fire academy cadets. Classic heatstroke tends to
affect the elderly or people who live in
poorly ventilated environments. Treatment consists of rapidly cooling the
patient by removing clothes, fanning
him or her, and by opening ambulance
windows. Check your local protocols or
speak with your medical director about
active versus passive cooling measures.
Some medications can alter the body’s
three mechanisms for dissipating heat.
Some common medications prevent the
body from increasing blood flow to the
skin, including psychiatric medications
(haloperidol, risperidone), amphetamines, cocaine and over-the-counter
decongestants. Beta-blockers can lessen
the heart’s ability to pump more blood
to the skin. Tricyclic antidepressants, cold
and allergy medicines, and some narcotics and amphetamines can decrease
sweating and ultimately lead to increased
body temperatures. Dehydration can be
increased by diuretics like furosemide
and HCTZ, and the caffeine in coffee and
certain soft drinks and energy drinks.
In 2008, heat illnesses were responsible
for more than 800 deaths across the U.S.,
so keep an eye on yourself, your partner
and your patients. Sometimes being hot
is not such a good thing.
Take this quiz, return it to an EMS educator for grading, and receive up to 0.50 hours of EMS CE credit!
1
2.
3.
4.
5. 6. 7. 8. Thermoregulator effectors affect the body’s temperature by vasodilating/vasoconstricting and sweating. True False
Heat cramping is generally a byproduct of excess salt. True False
Heat exhaustion can commonly result in a core body temperature greater than 104°F (40°C). True False
Heatstroke is a failure of the body’s cooling mechanisms. True False
Which of the following is not a form of heat transfer? a. convection b. dissipation c. conduction d. radiation
The body’s thermosensors are located in the… a. spinal cord b. skin c. muscles d. all the above
Signs of the heat exhaustion include all of the following EXCEPT: a. violent behavior b. headache c. fatigue d. tachycardia
Which of the following groups is not commonly affected by exertional heatstroke?
a. military recruits b. athletes c. elderly patients d. fire academy cadets
9. Which of these medications prevent the body from increasing blood flow?
a. psychiatric meds b. beta-blockers c. amphetamines d. all the above
10. Energy drinks such as Red Bull, Monster and Rock Star contain which commonly consumed diuretic?
a. corn syrup b. caffeine c. furosemide d. ginkgo biloba
MORE SHOTS FROM EMS MONTH
The fare was hearty,
the conversation a pleasure.
We were pleased to honor EMS
personnel with breakfasts,
lunches and dinners as we
celebrated EMS Month in May
at our hospitals. Top row: at
Littleton Adventist Hospital;
middle row: at Parker Adventist
Hospital; bottom row: at Porter
Adventist Hospital
Visit our website: www.emsteam.org
Join the EMS listserve: http://groups.google.com/group/coems/manage_promote