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Dangers of Adverse Environmental / Thermal

ConditionsPE 236

Juan Cuevas, ATC

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• Environmental _____ can adversely impact an athlete’s performance and pose serious health threats

• Areas of concern– _______________– _______________– Overexposure to the sun

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_______________

• Athletic trainers require knowledge and information concerning temperature, humidity and weather to adequately make decisions regarding environmental ___________

• Has caused a number of _____ over the years • Must manage heat stress appropriately• Hyperthermia = _______ in body temperature

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Heat Stress

• Extreme caution should be used when training in the heat (_________ could result heat stress)

• It is _________________• Athletes who train under these extreme conditions

are at risk• Physiologically the body will continue to function

if body temperature is maintained• Body must _____________ heat to maintain

homeostasis

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• Heat can be dissipated from the body through 4 mechanisms– Conduction (direct contact)– ____________ (contact with cool air or water

mass)– Radiation (heat generated from metabolism)– ___________ (sweat evaporating from the skin)

• Majority of body heat is dissipated through evaporation

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• Evaporative Heat Loss– ____________ allow water transport to surface– Evaporation of water takes heat with it– When radiant heat and environment

temperature are higher than body temperature, loss of heat through evaporation ________

– Air must be relatively ___________ for evaporation to occur

• relative humidity of 65% impairs evaporation• relative humidity of 75% stops evaporation

– ________________ can still occur in cold environment if body is unable to dissipate heat

• Caused by dehydration and inability to sweat

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Monitoring Heat Index• Heat, sunshine and humidity must be monitored

closely• Wet bulb globe temperature index (_______)

provides objective measure for determining precautions concerning participation in heat– WGBT incorporates different thermometer readings

• ___________ (standard mercury temperature)• ____________ (thermometer with wet gauze that is

swung around in air)

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– DBT and WBT can be measured with psychrometer (combines both thermometers)

• Wet bulb will be lower due to evaporation of water– Ventilation is provided by whirling

thermometer (sling psychrometer) – Newer models utilize digital sensors

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© 2005 The McGraw-Hill Companies, Inc. All rights reserved.

Heat Illnesses

• Heat ___________ (heat collapse)– Associated with rapid fatigue and

________________, ________ in heat for long periods of time

– Caused by peripheral vasodilation, or pooling of _______ in extremities resulting in dizziness and fainting

– Treat by placing athlete in cool environment, consuming fluids and laying down

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• Heat Cramps– Painful muscle _______ (calf, abdominal) due to

excessive water loss and electrolyte imbalance– Occurs in individuals in good shape who

_____________ themselves– Treatment

• Prevent by consuming ______ fluids and maintaining electrolyte ________

• Treat with fluid ingestion, light stretching with ice ___________

• Return to play unlikely due to continued cramping

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• Heat _____________– Result of inadequate fluid _____________– Will exhibit signs of _______ sweating, _____

skin, mildly elevated temperature, dizziness, hyperventilation and ____ pulse

– May develop heat cramps or become faint/dizzy– Core temperature will be ~102o

– Performance may ________– Immediate treatment includes fluid ingestion

(intravenous replacement, ultimately), place in cool environment

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© 2005 The McGraw-Hill Companies, Inc. All rights reserved.

• _____________– Serious _____-threatening condition, with unknown

specific cause– Characterized by sudden onset - sudden collapse, ______,

flushed _____ skin, minimal sweating, shallow breathing, _____ rapid pulse, and core temperature of > ______o F

– Temperature must be lowered within 45 minutes– Drastic measures must be taken to cool athlete

• Strip clothing• Sponge with cool water• Transport to hospital immediately… ______!!!

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© 2005 The McGraw-Hill Companies, Inc. All rights reserved.

Preventing Heat Illness• _____________ sense and precaution

– Consume fluids and ___________• Fluid and __________________ Replacement

– Single most important step taken by a coach to minimize the chance of heat illnesses

– Continual _________________ is critically important– Generally only 50% of fluid is ever replaced and should

therefore be replaced before, during, and after exercise

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– Fluid replacement should match ____________• Most effectively replaced at regular intervals (15 minutes)

– Time of stomach emptying is critical• Water is absorbed rapidly from intestine• Drink with 6% CHO is eliminated at the same rate if the individual is

hydrated• _________ drinks tend to empty rapidly and will not induce cramping• Drinks with caffeine and alcohol will promote _____________

– Hydration levels can be monitored via ________ color and volume

• Appropriate hydration = clear urine at normal or above-normal output level 60 minutes following exercise

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• Using Sports Drinks– _____ effective than just replacing fluids with water– Flavoring results in increased desire to consume– Replaces fluids and ______________– Small amounts of _______ help in retention of water– Different drinks have different nutrient levels– Optimal CHO level is 14g per ___ ounces of water– More CHO results in slower absorption– Effective for both short term and endurance activities

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© 2005 The McGraw-Hill Companies, Inc. All rights reserved.

• Gradual Acclimatization– Most effective method of avoiding heat stress– Involves becoming ___________ to heat and exercising

in heat– Early pre-season training and graded intensity changes

are recommended with progressive exposure over __________ day period

– 80% of acclimatization can be achieved during first 5-6 days with 2 hour morning and _____________ practice sessions

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• Identifying Susceptible Individuals– Athletes with ________ muscle mass– ____________ athletes – Athlete with increased fluid loss– While slight differences exist, precautionary measures apply to both

males and females– Athletes consuming medications or ___________ may have

impaired sweating and may predispose them to injury• Uniform Selection

– Base on temperature and ___________– Dress for the weather and temperature– _________ rubberized suits

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• Weight Records– Keep track of before and after measures for first

___________– If increase in temperature and humidity occurs

during the season, weights should again be recorded

– A loss of ________-% = reduced blood volume and could be a health threat

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_________________

Most activity allows for adequate heat production (increased metabolism) and dissipation, allowing for sufficient functioning

• Impact on warm-up and “_____________”• Temperature in conjunction with wind chill

and dampness or wetness can increase chances of _______________

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• With __________ fatigue, rate of exercise begins to drop and rate of heat loss relative to heat production may shift – Results in impaired neuromuscular responses and

_____________• Drop in core temp stimulates shivering but

stops after temp drops below _________oF• Death is imminent when temp falls below 77-

85oF.

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Cold Disorders• Fluid replacement is critical even under

colder environmental conditions– Dehydration = decreased _________ = less

fluid available for tissue _____________• May be useful to monitor weight of athletes

training in cold temperatures• While less common, injury/illness due to

the cold still occur, particularly in ____________ type activities, winter sports and swimming in cold water

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• _____________– Apparel geared for weather to provide semitropical

microclimate for body and prevent ________– __________ and windproof fabrics that allow passage

of heat and sweat, and allow movement– __________ and adjusting them are key to maintaining

body temperature (during period of (in-activity)– Inadequate clothing, improper warm-up and chill

factor can lead to injury, frostbite, and/or minor ___________ problems

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Overexposure to _______-

• Precautions must be taken to protect athletes, coaches, athletic trainers and support staff

• ____________ Effects on Skin– Premature aging and skin ________ due to

ultraviolet exposure– Premature aging is characterized by ________,

cracking and inelasticity of the ________– Skin cancer is the most common malignant

tumor found in ________-

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• Using _____________– Can help prevent damaging effects of UV radiation– Sunscreen effectiveness is expressed as _____ (sun

protection factor)• Indicates how many times longer an individual can be exposed to

the sun with vs. without sunscreen before skin turns _____.• The _______ the susceptibility, the higher the SPF that should be

used– Should be worn by ______, coaches, and athletic trainers

who are outside a considerable amount, and/or have fair complexion, light hair, blue eyes, or skin that ____________

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– Sunscreen use is at its highest March - November but should be used year round (particularly between the hours of ________)

– It should be applied _______ minutes before exposure and re-applied after exposure to water, excess __________, rubbing skin with clothing or a towel