Transcript Heat Illness PPT

HEAT RELATED
ILLNESS
Pediatric Emergency Medicine
Fellows Conference
June 18, 2015
Arnold Palmer Hospital for Children Orlando Health
Jose Ramirez, M.D., F.A.A.P
Pediatric Emergency Medicine
Arnold Palmer Hospital for Children
Jose Ramirez, M.D. has no financial disclosures
Objectives

Understanding effects of heat on the body

Mechanisms of Heat Dissipation

Types and classification of heat related illness

Failure of Thermoregulation

Management heat related illness

Unique characteristics of children

Prevention Strategies
Center for Disease Control Stats
CDC :2006

Five year period in the US 1999-2010

7,415 deaths associated with extreme heat
 618 deaths/year
 Majority were male 68%
– Mortality by age groups
 Highest mortality in the very young and very old
Thermoregulation

Hypothalamus
– Body’s thermostat
– Tight control
 Keep body temperature close to 98.6

Body Heat Generation
– Generates enough heat to elevate temp1 o C per hour
– Exercise may increase this by factor of 12

Heat Dissipation
– Crucial in maintenance of heat balance
– Hypothalamic action via autonomic nervous system
Aspects of Thermoregulation

Heat a byproduct
– Necessary metabolic processes
– Ambient temperature

Temperature control by anterior hypothalmus
– Via the autonomic system control of
 Vasodilatation dissipate by convection
 Sweat gland function dissipate heat by evaporation

Ability to compensate for heat production and stress
– Endogenous
– Exogenous

Increase body temperature
– Regulated event for physiological processes
– Heat production outpaces heat dissipation
Dissipation Mechanisms

Radiation

Conduction

Convection

Evaporation

Behavior/Developmental
Radiation

Transfer of energy via electromagnetic
radiation

No physical contact necessary

Less effective above 95o F
Evaporation

Heat transfer via conversion of
liquid to gas phase
– Boiling water
– Effective transfer of heat

Dependent on humidity level
– Lower humidity more effective
– Higher Humidity diminishes role

Primary means of heat dissipation

Enhanced by surface air flow
– Fans , Breeze
Conduction

Heat exchange by objects in direct contact
– Energy dissipation from higher to lower gradient

Thermal conductivity more effective
– Solids
 Ice packs at the groin
– Liquids
 Heat conduction enhanced by factor of 32 by immersion

Loss of effectiveness above 95o F deg
Convection

Transfer of heat energy by
movement of matter
– Gaseous
– Liquid

With heat the density of matter
changes
– Results in greater movement
– Heat transfer
Hyperthermia

Fever vs Hyperthermia
– Similar magnitude of temperature elevation
 Hyperthermia with higher maximum
– Differ in control of event
– Fever: physiologically well regulated event
– Hyperthermia: poorly or unregulated thermic event
 Heat stress event

Thermoregulatory system is stressed /overwhelmed
– Excessive production of heat
– Excessive environmental heat
– Impaired heat dissipation
Heat Related Illness
Categories

Minor heat Illnesses
– Heat rash
– Heat edema
– Heat cramps
– Heat syncope

Major Heat Illnesses
– Heat exhaustion
– Heat stroke
Heat Illness
Heat
Rash / Prickly heat
• Miliaria
•Children and infants
•Skin folds
•Obstruction sweat glands
•Erythematous and papular / fine pustules
Heat Cramps

Painful involuntary muscle spasms
– Calves, hamstring, quadriceps
– Prolonged and severe pain

Result after strenuous activity in hot environment
– Lack of Adequate stretching

Management
– Rest in cool environment
– Vigorous oral fluid replacement with electrolyte solutions
– Intravenous saline infusion

May be resistant to pain medications if dehydrated
Heat Syncope

Orthostatic hypotensive event
 Self limited condition
– Patient comes back to normal mental status
– Nonspecific symptoms
 Cold clammy skin
 Orthostasis
 Dehydration
– MENTAL STATUS IS NORMAL

Mildly elevated core body temperature
 Management
– Place in prone position,
– Rest, cool, IV hydration as needed
Heat Exhaustion
Most common form of heat related illness
 Thermoregulatory mechanism stressed
 Symptoms

– Malaise
– Orthostatic
– Nausea, headache, vomiting
– Syncope
– Cramps
– Normal or elevated (hyperthermia)
temperature
Two Types of Heat
Exhaustion



Water Depleted
Hypernatremic
Rapid Onset



– More common in athletes,
military personnel, laborers

Results from inadequate
fluid replenishment
– Intake of fluid lags behind
fluid loss
– Hypernatremic
Salt Depleted
Hyponatremic
Insidious onset
– Free water replacement
hydration

Hyponatremia secondary
poor salt intake
– Hydration preservation
attempted
– Cystic Fibrosis patients at
higher risk
Management
Remove from heat exposure
 Oral rehydration with electrolyte solution

– Intravenous for more severe cases

Typically mixed picture:
– Water and Salt depleted

Consider checking electrolytes
– IV fluids if necessary
Heat Exhaustion and Heat Stroke:
Continuum or Not?

Both as part of the heat induced illness
spectrum

Two different events
– Heat exhaustion victims may not have
elevated temps
– No current studies to demonstrate that
untreated heat exhaustion patients develop
heat stroke
Heat Stroke

Failure of body’s heat dissipation system
– Rapid rise of temperature
– Thermoregulatory failure

Reported mortality rate heat stroke
– As high as 80 % mortality
– Despite treatment mortality may be 10-12%
Heat Stroke Characteristics

Exposure to heat stress

Hyperthermic: (T> 104o F)

Neurological Dysfunction
– Altered mental status, seizures

Other findings
–
–
–
–
Tachycardia, normo/hypotensive blood pressure
Ocular abnormalities: dilation/fixed pupils; nystagmus
Tachypnea, hyperventilation
Nausea, vomiting, GI bleed
Two Forms of Heat Stroke

Classic: Non-exertional
– Summer heat waves
– Poor, elderly, infant, impaired mobility
 Infants in car seats

Exertional Heatstroke
– Strenuous physical activity
 Typically hot environment
– Adolescent or younger adult population
– Motivated, poorly acclimatized,
 Unconditioned athletes and military recruits
Classic Heat Stroke

Risk factors for non-exertional
– Dehydration
– Lack of air conditioning
– Underlying medical conditions
 Neurologic disorders / Poor cardiovascular status
 Hyperthyroidism / Obesity
– Impaired mentation
– CHILDREN:
 Lack self preservation skills
 Less developed sweating mechanisms
 Increased metabolic rates
Exertional Heat Stroke

Risks
– Involvement in strenuous activities
 High intensity exercise for short durations

Adolescents and young adults
– Highly motivated
– Poorly acclimatized
– Poorly conditioned

Chronic Medical Conditions increase risk
Pathophysiology of Heat Dissipation
Failure

Direct Toxicity to cells
– Protein denaturation
– Apoptosis and cellular death

Release of inflammatory cytokines
– Pathophysiology resemble sepsis
– Accumulation of inflammatory byproducts
 Production of cytotoxic agents
 Tumor necrosis factor

Injury to vascular endothelium
– Increased vascular permeability
– Leads to disseminated intravascular coagulation

End Result: Multiorgan System Failure
Severe Hyperthermia on Rodents
Mao et. al. 2004

Cerebral hypoperfusion and ischemia
– Arterial hypotension
– Intracranial hypertension

Neuronal cell damage
– Oxygen and nutrient deprivation
– Initiation of a neurotoxic cascade
 dopamine, serotonin, glutamate, glycerol
 nitric oxide, hydroxyl radicals, and/or cytokines

Possible venues to improve outcome
– Restoring perfusion
– Controlling release of neurotoxic substances
Characteristics of Heat Stroke
Mao et. al. 2004

Hyperthermia

Severe neurological abnormalities

Endotoxemia

Increased levels of cytokines

Multi-organ dysfunction
Multiorgan System Process

Neurologic

Cardiovascular
– Effects on cardiac output
– Effects on vascular integrity

Renal

Hematologic

Gastrointestinal / Hepatic
Neurological Signs

Neurological dysfunction
–
–
–
–

Ataxia
Disorientation
Seizures
Coma
CNS Pathophysiology
– Reduces cerebral blood flow during exercise
 Animal models
– Increased brain metabolism
 Build up of metabolic by products
– Increased blood brain permeability, edema
 increased ICP
 Herniation
Cardiovascular Manifestations

Cardiovascular
– Tachycardia, low systemic vascular resistance
– Myocardial depression

Dehydration

Maximal cutaneous dilatation
– Cardiovascular collapse

Younger circulatory system
 Seem more susceptible to heat stress
Pulmonary

Factors affecting pulmonary system
– Acidosis
– CNS stimulation
– Hypoxia

Tachypnea

Hyperventilation
Hematologic

Disseminated intravascular coagulation

Hemorrhagic complications

Consumptive process
• Increased vascular permeability
 Vascular Endothelial cell compromised integrity
Gastrointestinal and Hepatic
Issues

Hepatic and Renal Dysfunction
– Elevated transaminases and myoglobinuria

Gastrointestinal mucosal sloughing
– Ischemic gut
– GI bleed

Hepatic injury
– Elevated transaminases
– Hyperbilirubinemia
Renal

Impairment of renal function

Rhabdomyolysis signifcant cause
– Hyperkalemia or hypokalemia

Elevated core body temperature
– Acute tubular necrosis
 Renal insufficiency and diminished renal output
Heat Stroke and Systemic
Inflammatory Response

Bouchama et. al. 2002 NEJM article
– Elucidate Heat Stroke as type of SIR
– Endotoxin release from intestine
– Interleukin 1 and IL-6 release from muscles into
circulation
 Excessive leukocyte and endothelial cell activation
 Inflammatory and coagulation cascade set off
– Vascular enotheilal damage
– microthombosis
Scavenging Free Radicals
and Pre-conditioning
Chang et. al. 2007

Heat Stroke as a SIRS as starting point

Rats exposed to high environmental temperature
– Heat stroke damage: hyperthermia, hypotension, and cerebral ischemia
– Heat stroke damage
 Increased production of free radicals
 Higher lipid peroxidation

Pretreatment with hydroxyl radical scavengers e.g., magnolol
– Prevented increased production of hydroxyl radicals,
– Prevented increased levels of lipid peroxidation,
– Prevented ischemic neuronal damage in different brain structures

Training, as well as pretreatment with magnolol
– Minimizes the oxidative damage during heat stroke

Heat shock preconditioning
– Sublethal heat exposure or regular, daily exercise
 Induced overproduction HEAT SHOCK PROTEIN 72 in multiple
organs
– Attenuated the heat stroke-induced hyperthermia,
hypotension, cerebral ischemia
Heat Shock Protein
Up-regulation
Lee et. al. 2007
 Compared subjected three types of mice

– Over expression of HSP 72 gene ( [+]HSP72)
– No HSP 72 gene ([–]HSP72)
– Control Mice

Subjected mice to thermal stress (104 def F)
– Induced heat stroke

Survival times for [+]HSP72 significantly
exceeded those of [–]HSP72 or CM

Lee and Wen’s conclusions
– overexpression of HSP72 improves survival during
heatstroke
– Reduces hyperthermia, circulatory shock, and
cerebral ischemia and damage in mice

Implications:
– Can this be duplicated in humans having early
stages of heat stress
Heat stroke response seems similar to
endotoxemic syndrome
Leon et. al. 2007

Cytokines key modulators
– Acute phase response to stress, infection and inflammation

Cytokines implicated in the heat stroke pathophysiology

Lack of studies if antagonizing cytokines has benefit

Treating such patients as in endotoxic shock may have
benefits
– Immunomodulators such as interleukin-1 receptor antagonists
– Corticosteroids
– Recombinant activated protein C
Management of Hyperthermia

Chemical

Conductive

Evaporative

Radiation
Chemical

Antipyretics
 Interrupts the heat generated by inflammatory
process
– Acetaminophen
– Ibuprofen

Dantrolene
– Malignant hyperthermia
Radiation

Taking off clothing

Expose to ambient environment

Cool ambient environment
– Remove from direct radiation, ie sun exposure
Evaporative

Endothermic reaction in going from liquid
to gaseous face
– “sweat” water that evaporates takes off
greater energy
– Avoid alcohol baths
Mist fan with wetting the body
 Sponge bath

Convection
Arrange
convective
currents
•Dissipates Heat
Gas
•Set up air currents: wind;
fans
Liquid
•Water immersion
Conductive

Direct contact leads to heat transmission
– Placement in Tepid Bath
– Placement of cool moist towels
– Sponge bath
 Conductive sitting in water bath and evaporative
process from water on upper torso
– Tepid Water sufficient
– Towels soaked in ice and placed around neck
Management of Severly Ill


Removal of all clothing (radiation)
IV with fluid replacement: cool fluids

EVAPORATIVE COOLING
– Spray / wipe water on as much surface as possible
– Use fan pointed at patient

Conductive Cooling
– Ice Packs on Groins and Axillas
– Towels soaked with Ice water for covering
– ICE BATH Immersion
 Controversial
 Limitations: difficult to access and monitor patient
 Shivering and shunting to core may occur
Ice Water Immersion

Exertional heatstroke
 Immersion in iced
water
 Placing patient in a tub
of iced water
 Massaging Extremities
– promotes vasodilatation
– heat loss
Other Conductive Cooling
Methods

Non invasive techniques
– Cooling blankets or ice packs coverings
 All or partial
 Covering areas of proximal large vessels
– Neck, groin, and axilla

Invasive techniques
– Core Cooling
– Chilled intravenous fluids
– Iced lavage
 gastric , colonic, bladder or peritoneal
Core Cooling

Conductive in nature

Cold saline peripheral infusion

Ice water lavage
– Conductive means
– Requires intracavitary access
– Gastric , bladder , colonic, peritoneal

More invasive therefore more risk
– Recall skin is the largest organ lavage
Priorities
ABC’s: Protect the airway
 Definitive airway control

– Obtundation
– Poor ventilation

Oxygen: alleviates elevated oxygen
consumption in the hypermetabolic state
 Monitoring:
– Cardiovascular with pulse oximetry
– Continuous temperature
 (rectal, bladder, esophogeal probe)
 Thermometer should record above 106°F

Rapid cooling measures
– Target temp 101°F
 Slow down active cooling at 102 °F
 Avoid overshooting into hypothermia
– Decreases mortality

Continuous reassessment:
– Mental status
– Perfusion
– Cardiovascular status: pulses need for
inotropic or vasopressor support
– Urine output

Diazepam 0.1 mg/kg/dose for shivering
Ancillary Studies
.

Labs to order:
• CBC with Plt
• Electrolytes with Ca, BUN, Crt
• Coagulation Studies
 Fibrinogen
 Fibrin split products
• Lactate, LDH and CPK
• Liver Transaminases
What is Most Effective
Bouchama et. al. 2007

Review looking clinical studies on management
of heat stroke
– Total of 556 patients in 19 studies

Conductive cooling, immersion in iced water
– Effective
 young, military personnel and athletes with exertional
heatstroke

Cooling method did not affect outcome in classic
heatstroke
– Non-invasive, evaporative or conductive based

No evidence for specific endpoint temperature
Consider Other Factors
Exacerbating Heat Stress

June 1998 heat wave in New Orleans,
– ambient temperature exceeded 91.9 degrees F
– heat index 112 degrees

Two wk period: 8 admits for Heat Stroke
– Six patients (75%) rhabdomyolysis;
– Three patients with DIC
– Two deaths

Six patients with meds/drugs that may cause elev temp
–
–
–
–
cocaine
diphenhydramine,
tricyclic antidepressants, and
phenothiazines.
Heat Stroke Prognosis

High Mortality:
–
–
–
–

Prolonged coma, coagulopathy, renal failure
Severe hypotension, delayed seizures
Core body temp greater than 106°F
Early high levels of hepatic transaminases
Regain consciousness in 4-10 hrs
– May have hepatic / renal dysfunction
– Neurologic sequalae, ie. cerebellar ataxia thermoregulation
instability

Diminished level of consciousness <3 hrs
– Rapid and full recovery
Treatment of Heat Stroke

Cool the patient until core temperature is
<102.2°F(39°C)
 Rehydrate with intravenous fluids
 Administer vasopressor therapy if shock persists after
rehydration
 Monitor for anemia and thrombocytopenia
 Treat coagulopathy if clinical hemorrhage is present
 Treat seizures
 Monitor for cerebral edema
 Institute mechanical ventilation for respiratory failure
 Liver transplantation not indicated for severe liver
How are Kids at Risk?


Physiological response and magnitude of response differ
Differences include
• Greater surface area-to-mass ratio,
• Higher metabolic rate
 More heat generation per kg
•
•
•
•
•
Inability to increase cardiac output,
Greater ability to alter peripheral blood flow,
Lower blood volume
Blunted thirst response
Lower amount of sweat produced per gland
 Reduced ability to dissipate body heat
• Slower Acclimatization
• Inability to move to less stressful environment
 Physically
 Psychologic

More complex diagnostic scenario

Absence of appropriate history

Consider other entities
– Status Epilepticus
– Meningitis / sepsis
– Toxins like anticholinergics
– DKA
Four Decades of Struggle
Kids and Car Heat

1976 Roberts described heat stress potential of parked cars
on an 83 deg day
– Measured temperature in parked cars
 Windows open slightly and half way
 In direct and non-direct sunlight

“Thermal Burden” of poorly ventilated cars
– Opening window essentially ineffective
– Within 45 minutes temperature up by 20-30 in 3 groups

Educational Survey: 50 mothers interviewed
– 10 of 50 acknowledge on having left child in parked car

Stressing the importance of education
– The thermal risk to children in parked cars
Heat-Children-Cars
Deadly Combo

1998-2010: 450 heat related deaths of
children left in automobiles in the US
– Average 37 deaths per year
 2009: 33
 2010: 49

Mostly in Southern parts of country
Circumstances

1998-2015: 636

Unfortunate
– 53% (336): "forgotten" by caregiver
– 29% (186): playing in unattended vehicle
– 17% (110): intentionally left in vehicle
– 1% : circumstances unknown (4 Children)

ALL PREVENTABLE
Ages of Automobile Related
Hyperthermic Associated Deaths

Less than 1 yr.
197cases (31%)

Toddler (1-4yr)
389 cases (61%)

Young Child (5-10)
42 cases (7%)

Older Child (>11yrs)
7 cases (1%)
Breakdown by Age

Below 1 yr = 30% (133)

7-years old = 1% (2)

1-year old = 24% (108)

8-years old = 1% (2)

2-years old = 19% (85)

9-years old = 1% (2)

3-years old = 12% (54)

10-years old = 1% (3)

4-years old = 6% (27)

11-years old = 1% (2)

5-years old = 3% (14)

12-years old = < 1% (1)

6-years old = 2% (8)

13-years old = < 1% (1)

Unknown = 1% (2)

Incident #DateLocationTemperatureNameAge November 2910-NovForest
City, NC83°An’niya Miller4 yr2810-NovForest City, NC83°Bry'asia Shepard2 yr2710NovForest City, NC83°Asia Shepard2 yr August 2631-AugValdosta, GA94°Dejuan
Ramsey1 yr2525-AugDeFuniak Springs, FL92°Carolyn Martin23 mo2425AugCarrolton, TX103°Beckham Flanagan10 mo2317-AugKosciusko, MS98°Amila
Hubbard 2 yr2215-AugShreveport, LA102°Michael Dupaquier 2 yr2110-AugStuart,
FL91°Harold Lima21 mo209-AugMemphis, TN100°Hunter Hicks15 mo198-AugLindale,
TX97°Kerrigan Petty4 mo182-AugTopeka, KS102°Vidal Vela23 mo172-AugGrange
City, KY81°Kaleb Davis 18 mo July 1631-JulyOsage, MN93°Katherine Larson3
yr1528-JulyPasadena, TX94°Jasmine Alvarez2 yr1420-JulyBalch Springs,
TX102°Jacob Fox4 yr1316-JulyMcAllen, TX99°Tyler Ramierz2 yr1215-JulySouth Bend,
IN90°Abraham Barlue3 yr11*2-JulyKansas City, MO97°Jesse Snyder9
yr June 1030-JuneCache, OK97°Kairina Kraft5 yr930-JuneCache, OK97°Kianna
Diggs6 yr828-JuneGrand Forks, ND78°Kate Boe5 mo722-JuneDeQueen,
AR94°Zachary Bowden14 mo621-JuneTucson, AZ100°Jesse Hayes10 yr518JuneStillwater, OK96°Banyan Roberts21 mo May 428-MayKnox County,
TN90°Brian Womack3 yr316-MayWeslaco, TX86°Deandra Hernandez8 moApril229AprLake Worth, FL80°Seanna Lopez14 mo14-AprAiken, SC75°Zachary Frison15 mo
http://ggweather.com/heat/
29 Deaths
36 total deaths
http://ggweather.com/heat/
,
http://ggweather.com/heat/
43 total deaths
http://ggweather.com/heat/

33 cases
http://ggweather.com/heat
49/
http://ggweather.com/heat/
33
http://ggweather.com/heat/
34
http://ggweather.com/heat/
44
http://ggweather.com/heat/
30
Heat Stress from Enclosed
Vehicle: another view
McLaren, C 2005

In enclosed vehicles in varying ambient temps
(72-96o F) evaluate over 60 minutes
– The degree of temperature rise
– Rate of temperature rise

Rate of temperature rise did not vary much with
difference in ambient temperature
– Mean avg increase of 3.2o F per 5 min interval
– 80% of temp rise during the first 30 minutes

Final temperature was dependent on starting
ambient temperature
– On average 40o F increase in internal temperature
Representative vehicle temperature rise over time.
Catherine McLaren et al. Pediatrics 2005;116:e109-e112
©2005 by American Academy of Pediatrics
Interior vehicle temperature over time: closed versus cracked windows.
Catherine McLaren et al. Pediatrics 2005;116:e109-e112
©2005 by American Academy of Pediatrics
Fatalities in Car Trunk
Entrapment
JAMA 1999

Nine cases of fatal car trunk entrapment 19871998
– 19 children died in these incidents
– Cause of death hyperthermia or asphyxia
– Three incidents from summer of 1998

8 of the episodes occurred temp>90
 Ages of involved children were less than 6
 Preventable deaths
– Typically children playing around / in cars
Prevention

Child safety tips

Acclimatization

Public health measures

Legislation
Child Safety Tips

Stay indoors on very hot humid days

Wear light-colored loose fitting clothing

Wear a hat

Parasol (umbrella)

Avoid over bundling

Vehicular Safety
Outdoor Activities

Restricting duration of intense activity
– During elevated humidity and temperature.
– Limit to 15 minutes

Preload with fluids before exercise
– Avoid drinking high-osmolar fluids
 sodas and high-sugar drinks
 which can stimulate water loss.

Wear appropriate material
– One layer of absorbent, lightweight, light-colored
– Allows for evaporation.
– Sweat-saturated clothing should be changed regularly
Vehicular Safety





Never leave in car unattended
No playing in or around
vehicles
Check seat/buckle to assure
not hot
Check all passengers left car
Always lock vehicles
Acclimatization

Physiological changes
– Increases
 plasma volume
 rate of sweating
 capacity for cutaneous vasodilatation
– Decreases




Threshold for initiating sweating
Electrolyte component of sweat
Heart rate
Core body temperature

Induced by repetitive exposure to heat stress
 1-2 week process
 Transient State:
– 4 weeks after removal of heat stress
Laws Prohibiting Unattended
Children in Vehicles
Institute Public Measures
Meteorological Public Health
Warning

Excessive Heat Watch
– Conditions are favorable for an excessive heat event to meet or
exceed local Excessive Heat Warning criteria in the next 24 to
72 hours.

Excessive Heat Warning
– Heat Index values are forecast to meet or exceed locally defined
warning criteria for at least 2 days (daytime highs=105-110° F)

Heat Advisory
– Heat Index values are forecast to meet locally defined advisory
criteria for 1 to 2 days (daytime highs=100-105° F).

Reviewed effects of heat on body

Overview of mechanisms of dissipating heat

Reviewed the diagnosis and management of heat
cramp, heat exhaustion, and heat stroke

Reviewed the unique characteristics of children

Public Health awareness and prevention strategies
Any Questions






















Bouchama A et. al. Cooling and hemodynamic manaagement in heatstroke: practical recommendations. 2007.
Critical Care. 11 (3)
CDC :Heat-Related Deaths --- United States, 1999—2003. MMWR 2006;55 (29):796-798
CDC :Heat-Related Deaths --- Arizona 1993, and United States, 1979—2002. MMWR 2005;54 (25):628-630
CDC Report:Fatal Car Trunk Entrapment Involving Children—U.S., 1987-1998. 1999JAMA Vol. 281 No. 6
Chang CK. Chang CP. Liu SY. Lin MT. Oxidative stress and ischemic injuries in heat stroke. [Review] [68 refs]
[Journal Article. Research Support, Non-U.S. Gov't. Review] Progress in Brain Research. 162:525-46, 2007.
EDEN PRAIRIE, CNN News Aug 2001
http://www.crh.noaa.gov/lmk/?n=noaaexcessiveheat
Glazer JL. Management of heatstroke and heat exhaustion. [Review] [32 refs] [Journal Article. Review] American
Family Physician. 71(11):2133-40, 2005 Jun 1
Grubenhoff JA. et. al. Heat-Related Illness. 2007. Clinical Pediatric Emergency Medicine - Volume 8, Issue 1
Hoffman J. Heat-Related Illnesses in Children. 2001 Clinical Pediatric Emergency Medicine - Volume 2, Issue
Kids Health from Nemours www.KidsHealth.org
Jardine DS. Heat Illness and Heat Stroke. Pediatr. Rev. 2007; 28; 249-258
Lee WC, Wen HC, et. al. Heat Shock Protein 72 Overexpression protects against hyperthermia, circulatory shock,
and cerebral ischemia during heatstroke. Appl Physiology. 2006. 100:2073-2082
Leon LR. Heat Stroke and Cytokines. Progress in Brain Research. 162: 481-524, 2007
Lin J, Losey R, Prendergast H. An Evidence Based Approach to Hyperthermia and Other Heat Related
Emergencies. Ped Emerg Med Pract. 2009 6(4)
Martinez M. Devenport L. Saussy J. Martinez J. Drug-associated heat stroke. [Review] [27 refs] [Journal Article.
Review] Southern Medical Journal. 95(8):799-802, 2002 Aug.
Mao-Tsun Lin International Thermal Physiology Symposium: Physiology and Pharmacology of Temperature
Regulation . Journal of Thermal Biology. 2004. 29 (7) 463-469
McLaren C., et. al. Significant Temperature Rise in Enclosed Vehicles Heat Stress From Enclosed Vehicles:
Moderate Ambient Temperatures Cause. Pediatrics 2005;116;e109-e112
Roberts KB., et. al. The Automobile and Heat Stress. Pediatrics. 1976; 58; 101-104
Younggren B, Yao C. The Evaluation and Mangement of Heat Injuries in the Emergency Department. Emer Med
Pract 8(6)
Stewart C: The spectrum of heat illness in children. Pediatr Emerg Med Rep 4:41-52, 1999.
http://ggweather.com/heat/
Med Sport Sci. 2011;56:126-49. doi: 10.1159/000320645. Epub 2010 Dec 21.
Temperature regulation and elite young athletes.
Falk B1, Dotan R.
Author information
•1Faculty of Applied Health Sciences, Brock University, St. Catharines, Ont,
Canada. [email protected]
Abstract
Children and adults employ different thermoregulatory strategies, particularly
in dealing with heat stress. Children rely more on 'dry' heat exchange, while
evaporative heat loss is adults' foremost heat-dissipation venue. Several
anatomical, physiological, and psychological factors can affect differential risk
of thermal injury in the child vs. the adult athlete, in some situations. Children
have greater surface-area- to-mass ratio, lower sweating rate, higher
peripheral blood flow in the heat, and a greater extent of vasoconstriction in
the cold. They can acclimatise to a similar extent but do so at a lower rate
than adults. Differences in perceived exertion and thermal strain, cumulative
experience, cognitive development, and decision-making capacity may
negatively affect the young athlete's behaviour under competitive and other
situations, possibly subjecting him/her to sub-par performance or to greater
risk of thermal injury. However, except for very limited environmental
conditions, children in general, and young athletes in particular, are