Final - Environmental Considerations Flashcards
hyperthermia
prone
ex
elevated body temp
football, longdistance runners
Vikings - Corey stringer that took stimulants and died
heat stress
preventable
exercising in hot, humid environments
when outside of body temp - denature of protein and wonky physiological processes
needs to be able to dissipate heat
body temp can be affected by
metabolic heat production = ages and conditions conductive heat exchange convective heat exchange - gas radiant heat exchange evaporative heat loss
BMR
basal metabolic rate - min energy required to sustain body’s vital functions - basic lvl of heat production on chemical rxns of metabolism
muscular activity and heat production
side effect to BMR
strenuous PA - increase BMR 5 times the normal rate
hormones and BMR
several can increase - menopause
stress hormones and thyroxine increase BMR
dietary intake in metabolic rate
increase - works to digest food
conduction
transfer of heat by direct contact
proportional to SA, temp diff, and density of surrounding
convection
movement of molecules from warm to cool - wind chill
proportional to temp gradient and air flow
radiant
heat from sun increases body temp
body dissipates heat through dilating superficial capillaries
evaporation of sweat
trap and reduce heat when evaporated by 0.58kcal/ml - fat ind insulates the heat
proportional to SA, temp diff
inversely proportional to humidity
rise in core temp -> hypothalamus -> SNS -> increase sweat
water vapor in expired air
cools the body - you will lose water and weight through breathing
if you are running and dont sweat anymore
sign of heat stroke
replenshing fluids
1:1
heat index
wet bulb globe temp
dry bulb temp - mercury thermometer
wet bulb temp - wet wick/gauze at the end of thermometor and swung in the air
over 90 all training must be stopped
heat exhaustion
exercise in heat and humidity that increases the body temp secondary to heat from muslce work
dehydration or humid environment affects sweating therefore heat loss
4 at risk of heat illness
hot and humid
dehydration
lack of fitness
unacclimatized - at least one day before
mild heat illness - 3
heat fatigue - tiredness and weakness, occasionally headache - drink more water , vessels are dilated so dont get up and run
heat cramps - muslce tightness and spasms, usually calf and thigh
heat syncope - fainting episode immediately after exercise
moderate heat illness
heat exhaustion - weakness, headache, dizziness, nausea - occasional mild confusion
Loss of consciousness - if cont - mild reduction in BP and increase in HR
severe heat illness
heat stroke - reduced consciousness
hot dry skin
low BP and rapid pulse
diagnosis of heat illness
urgent consult with sports physician, usually clinical but electrolytes may be lost
treatment of mild heat illness
stop, elevate legs, cool drinks
treatment of mod heat illness
stop, shelter from heat, ice to neck armpits and groin, cool drinks
treatment of severe heat illness
stop, remove from environment, ice to neck, armpits and groins, fluid replacement
conscious - cold fluids - glucose/electrolyte, 5% glucose or water downed tomato juice
unconscious - intravenous fluids
may hospitalize
7 preventing heat illness
fluid and electrolyte replacement gradual acclimatization identify susceptible ind wicking uniforms weight records temp and humidity readings fluid and electrolyte balance
fluid and electrolyte balance
athletes need to replenish fluids bc they sweat regardless
cold more readily absorbed
hypohydration - decreased muscular strength and endurance, decreased blood and plasma volume, altered cardiac function, loss of electrolytes
commercially prepared drinks - slow gastric emptying due to sugars
activities >45 mins from 5% solution of polymerized glucose - before and after competition
gradual acclimatization
accustomed to heat and exercise in hot temps
preseason program before competition
susceptible ind
large muscle mass/overweight
poor fitness, hx of heat illness and sick
uniforms
light weight - polypropylene to wick sweat away
weight records
1.1-1.5% of water can be lost before you see a drop in performance
3-5% drop in blood volume, only allowed to cut 5%
temp and humidity
DBT and WBT should be taken before and after exercise - then modify practice
hypothermia
reduction in core body temp
when it loses more heat than it can produce
4 ways to lose heat
conduction
convection
radiation - loss to nearby objects
sweating - evaporation
3 at risk for hypothermia
water, alpine, endurance sports
mild hypothermia - 6
cold extremities shivering increased HR and BR urgent desire to pass urine slight uncoordination
mod hypothermia - 7
tiredness and weakness increased uncoordination reduced shivering and slurred speech poor mem drowsiness, poor judgment dehydration
severe hypothermia - 7
stop shivering inappropriate B reduced consciousness muslce ridigidy low BP and HR irregular HR fluid accumulation in lungs
treating mild hypothermia
remove from cold
remove all wet clothing and cover with dry blankets - if cant - put them in a plastic bag below the neck
space blanket
warm drinks
treating mod hypothermia
remove from cold remove all wet clothing and cover with dry blankets - if cant - put them in a plastic bag below the neck space blanket gentle hospital
treating severe hypothermia
gentle
urgent transfer to hospital
ICU and active rewarming with close monitoring
dangers of hypothermia
irregular HR - artial fibrilation, ventricular fibrillation
pulmonary edema - fluid in lungs
aspiration - foreign body into lungs
increased risk of muscular tear - decreased flexibility
numbness and impaired coordination
decreased energy availability - inhibition of breakdown of energy stores
7 prevention of hypothermia
avoid activity inappropriate for fitness lvls avoid activity to exhaustion avoid dehydration ensure adequate nutrition appropriate clothing warm up appropriately plan and communicate with others
frost bite
freezing of tissues due to exposure of extreme cold - peripheries
superficial - superficial layers of skin
deep - full thickness of skin and deeper issues
risk for frost bite
activities in extreme cold - alpine events
symptoms of superficial frost bite
burning local pain
numbness
pale and grey skin - red after thawing
blisters
symptoms of deep frost bite
extreme pain
numbness
frozen block of hard white tissue with areas of gangrene and blood blisters if severe
treatment of superficial frost bite
thaw but direct contact with body heat - dont thaw unless prevention of refreeze - dont rub
treatment of deep frost bite
hot water bath - whirlpool with antiseptic hospitalization pain killers antibiotics for infection special intravenous fluids delayed surgery
