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Heat Intolerance Heat Intolerance ProblemsProblems
Kambiz Behzadi, M.D.Kambiz Behzadi, M.D.
Orthopaedic SurgeonOrthopaedic Surgeon
Fremont/PleasantonFremont/Pleasanton
What Causes Heat Related Illness?What Causes Heat Related Illness?
Body’s failure to keep itself coolBody’s failure to keep itself cool Sweat/Evaporation releases heatSweat/Evaporation releases heat Humidity impairs release of heatHumidity impairs release of heat Increased body temperatureIncreased body temperature Heat IllnessHeat Illness
Heat IntoleranceHeat Intolerance
> 300 people die of heat related > 300 people die of heat related illness in U.S.illness in U.S.
Heightened awareness in athletesHeightened awareness in athletes Identify athletes at riskIdentify athletes at risk Not a diseaseNot a disease Accident waiting to happenAccident waiting to happen
Heat IntoleranceHeat Intolerance
Heat Stroke can occur in best Heat Stroke can occur in best athletesathletes
Korey Stringer, Vikings, professionalKorey Stringer, Vikings, professional Estrate Autin, Florida, collegeEstrate Autin, Florida, college
Heat IntoleranceHeat Intolerance
Preseason Football, Marathon, SoccerPreseason Football, Marathon, Soccer Mild to FatalMild to Fatal High Temperature + High HumidityHigh Temperature + High Humidity Preventable awareness, Preventable awareness,
recognition, treatmentrecognition, treatment
HypothalamusHypothalamus
Body’s ThermostatBody’s Thermostat As temperature hypothalamus As temperature hypothalamus
responds:responds: 1. Increase 1. Increase blood flow to skinblood flow to skin 2. Increase 2. Increase sweatingsweating
Temperature RegulationTemperature Regulation
Conduction: jumping into the poolConduction: jumping into the pool Convection: standing in front of fanConvection: standing in front of fan Evaporation: water from liquid to gasEvaporation: water from liquid to gas Radiation: electromagnetic heat Radiation: electromagnetic heat
waveswaves
Temperature RegulationTemperature Regulation
ConductionConduction
Temperature RegulationTemperature Regulation
ConvectionConvection
Temperature RegulationTemperature Regulation
Sweating & Sweating & EvaporationEvaporation
Temperature RegulationTemperature Regulation
RadiationRadiation
Sweating/EvaporationSweating/Evaporation
In hot a environment, In hot a environment, EvaporationEvaporation becomes the becomes the Primary sourcePrimary source of of Heat Heat DissipationDissipation
Humidity Humidity decreasesdecreases our ability to our ability to get rid of get rid of HeatHeat
Exercise Work + HeatExercise Work + Heat
Heat increases Heat increases corecore body body temperaturetemperature
Warm blood bathes the Warm blood bathes the hypothalamushypothalamus
Blood diverted from warmBlood diverted from warm core core to to cool cool shellshell (conduction, convection, (conduction, convection, radiation)radiation)
Sweat glands release hypotonic Sweat glands release hypotonic saline solution (sweat) evaporationsaline solution (sweat) evaporation
PhysiologyPhysiology Exercise work + heatExercise work + heat
HypothalamusHypothalamus
Blood Flow SkinBlood Flow Skin
SweatSweat
Hot EnvironmentHot Environment
Sweat/EvaporationSweat/Evaporation
ConductionConduction
ConvectionConvection
Radiation Radiation
Exercise in Heat Two Demands Exercise in Heat Two Demands on Circulatory Systemon Circulatory System
Blood (Nutrients and Oxygen) to Blood (Nutrients and Oxygen) to Working MuscleWorking Muscle
Blood to Skin to Cool BodyBlood to Skin to Cool Body
Heat and ExerciseHeat and Exercise
MuscleMuscle
G.I. Tract KidneyG.I. Tract Kidney
Circulatory SystemCirculatory System
Liver BrainLiver Brain
Skin Skin
Early Heat IntoleranceEarly Heat Intolerance
ShockShock: Weak pulse, low blood : Weak pulse, low blood pressure, dizziness, syncope, pressure, dizziness, syncope, headache, nausea, vomiting, lack of headache, nausea, vomiting, lack of appetite, weaknessappetite, weakness
Temperature below Temperature below 102102 FF or or 39 C39 C
Stressed Out Circulatory SystemStressed Out Circulatory System
Dehydration & Fluid LossDehydration & Fluid Loss
Worsening State of ShockWorsening State of Shock
Heat Stress + ExerciseHeat Stress + Exercise
Overwhelmed Cardiovascular SystemOverwhelmed Cardiovascular System
Heat ExhaustionHeat Exhaustion
Heat StrokeHeat StrokeBreak down cooling mechanism Break down cooling mechanism
Increase core body temperature Increase core body temperature ++ Shock Damage to cells in body Shock Damage to cells in body Multi-system failure Death Multi-system failure Death
Heat Intolerance ProblemsHeat Intolerance Problems
Heat SyncopeHeat Syncope Heat CrampsHeat Cramps Heat ExhaustionHeat Exhaustion Heat StrokeHeat Stroke
Heat SyncopeHeat Syncope
Athlete stands still after exerciseAthlete stands still after exercise Pooling of blood in extremitiesPooling of blood in extremities Light-headed, dizzy, faintLight-headed, dizzy, faint Core body temperature is normalCore body temperature is normal Lie on ground, shaded area, legs Lie on ground, shaded area, legs
elevatedelevated Oral fluids usually not requiredOral fluids usually not required Recovery rapidRecovery rapid
Heat Syncope TreatmentHeat Syncope Treatment
Heat CrampsHeat Cramps
Painful contractions large muscle groups Painful contractions large muscle groups ( legs, abdomen) ( legs, abdomen)
Dehydration & Loss of balance between Dehydration & Loss of balance between saltsalt and and water water in musclein muscle
Treatment: Treatment: 1. Rest and Passive stretch1. Rest and Passive stretch2. Fluid replacement (water, sports drink)2. Fluid replacement (water, sports drink)
Prevention: Adequate hydration Prevention: Adequate hydration beforebefore and and throughoutthroughout exercise exercise
Heat Cramps TreatmentHeat Cramps Treatment
Heat ExhaustionHeat Exhaustion
Most common form of heat Most common form of heat intoleranceintolerance
Fatigue, weakness, sweating, Fatigue, weakness, sweating, nausea, diarrhea, mental status nausea, diarrhea, mental status normal to slightly impairednormal to slightly impaired
Symptoms of mild shockSymptoms of mild shock Temperature < 102 F or 39 CTemperature < 102 F or 39 C
Heat Exhaustion TreatmentHeat Exhaustion Treatment
Lie in cool, shaded areaLie in cool, shaded area Fluid replacementFluid replacement IV FluidsIV Fluids Do not allow return to vigorous Do not allow return to vigorous
activity until activity until normal body weightnormal body weight is is reachedreached
Heat StrokeHeat Stroke
True True Medical EmergencyMedical Emergency Hyperthermia (Temp>105F or >40C)Hyperthermia (Temp>105F or >40C) Failure of Thermoregulatory Failure of Thermoregulatory
MechanismMechanism Central Nervous System DysfunctionCentral Nervous System Dysfunction Second most common cause of death Second most common cause of death
in U.S. athletein U.S. athlete
Animals Built-in Protective Animals Built-in Protective Mechanism Mechanism
Exercise + Heat Mild ShockExercise + Heat Mild Shock
Fluid Loss andFluid Loss and Shock DehydrationShock Dehydration
Overwhelming TemperatureOverwhelming TemperatureHeat regulatoryHeat regulatoryMechanismMechanism Metabolism Metabolism
Diagnosis Heat Stroke: Rectal Diagnosis Heat Stroke: Rectal Temp > 105 FTemp > 105 F
AggressivenessAggressiveness IrritabilityIrritability Emotional Instability and hysteriaEmotional Instability and hysteria ApathyApathy DisorientationDisorientation Unsteady gaitUnsteady gait Hot, dry skinHot, dry skin UnconsciousnessUnconsciousness
Treatment Heat StrokeTreatment Heat Stroke
Call AmbulanceCall Ambulance Remove clothingRemove clothing Immerse in cool/iced water bathImmerse in cool/iced water bath Cover wet sheets and compress+fanCover wet sheets and compress+fan Airway, Oxygen, RehydrationAirway, Oxygen, Rehydration Support Multi-organ failureSupport Multi-organ failure
PreventionPrevention AcclimatizationAcclimatization: body’s adaptation : body’s adaptation
to heat stress, and increased to heat stress, and increased capacity to work in high temperature capacity to work in high temperature and humidityand humidity
7 days to several weeks7 days to several weeks 30 minutes 2 hours30 minutes 2 hours Lower resting body temperatureLower resting body temperature Increased plasma volumeIncreased plasma volume Lower threshold for sweatingLower threshold for sweating
PreventionPrevention
Practice in early morning or late Practice in early morning or late afternoonafternoon
Night games early in seasonNight games early in season Uniforms light weight, porous, light in Uniforms light weight, porous, light in
colorcolor Sleeves short and socks lowSleeves short and socks low Much skin exposed to airMuch skin exposed to air
PreventionPrevention HydrationHydration is key is key Free intake of fluids during gamesFree intake of fluids during games Regular fluid breaks no less than every half hourRegular fluid breaks no less than every half hour 1 pint1 pint (2 cups) for each (2 cups) for each 1 pound1 pound sweat lost sweat lost 10 oz. Every 30 minutes10 oz. Every 30 minutes Only 50% fluid loss made up by thirstOnly 50% fluid loss made up by thirst (encourage (encourage
fluid intake fluid intake betweenbetween and and duringduring sessions) sessions) Events < 90 min, electrolyte replacement usually Events < 90 min, electrolyte replacement usually
unnecessaryunnecessary
PreventionPrevention
Glucose concentration < 5% to 8%Glucose concentration < 5% to 8% Dilute twofoldDilute twofold 10% glucose (soft drinks and juices) 10% glucose (soft drinks and juices)
cause stomach cramps, nausea, cause stomach cramps, nausea, diarrhea, slow gastric emptyingdiarrhea, slow gastric emptying
Fructose (fruits) absorbed slowly and Fructose (fruits) absorbed slowly and causes G.I. distresscauses G.I. distress
PreventionPrevention
Sports drinksSports drinks Replacement glycogen in (muscle Replacement glycogen in (muscle
and liver) in exercise lasting > 90 and liver) in exercise lasting > 90 minutesminutes
Dilute solution Sodium and Glucose Dilute solution Sodium and Glucose increase absorption of water in small increase absorption of water in small intestineintestine
PreventionPrevention Cumulative HypohydrationCumulative Hypohydration Weigh before and after each practiceWeigh before and after each practice No player should be allowed to return No player should be allowed to return
to play until to play until fluid loss is replacedfluid loss is replaced and and normal weight is achievednormal weight is achieved
Electrolyte Make-upElectrolyte Make-up
Goal to replace sweat that has evaporatedGoal to replace sweat that has evaporated Sweat = water + small concentration of Sweat = water + small concentration of
salts and other electrolytessalts and other electrolytes Concept: Sport drink = SweatConcept: Sport drink = Sweat Evaporated sweat replaced before next Evaporated sweat replaced before next
exerciseexercise Normal diet replaces lost electrolytesNormal diet replaces lost electrolytes Electrolytes in drinks increase absorption Electrolytes in drinks increase absorption
of waterof water