Chapter 6 - Environmental Conditions Flashcards
Hyperthermia
elevated body temperature
metabolic heat production
normal metabolic function causes production and radiation of heat; level of increasing body heat depends on intensity of physical activity
conductive heat exchange
physical contact with other objects can result in a heat gain or loss
convective heat exchange
heat loss or gain depending on temperature of circulating medium
radiant heat exchange
from sunshine
evaporative heat loss
water is transported to surface via sweat glands, where it evaporates, taking large quantities of heat with it
when is evaporative heat loss impaired?
when humidity reaches 65%. It is impossible at 75%.
normal sweat rate
1 quart/hour for 2 hours (varies per person and situation)
what is the heat index
temperature do to heat/humidity/ and sunshine
WBGT
wet bulb globe thermometer
dry bulb: recorded from standard mercury thermometer
wet bulb: uses wet wick or piece of gauze wrapped around end of thermometer that is swung around in the air
globe temperature: measures the sun’s radiation and has a black metal casing around the end of a thermometer
psychrometer
consists of 2 thermometers - dry and wet - where the cloth is soaked and thermometers are properly ventilated, WBT
heat rash
red, raised rash with sensations of prickling and tingling during sweating
occurs where skin is wet
localized to areas covered by clothing
drying off can help prevent rash
heat syncope
rapid physical fatigue during overexposure to heat
peripheral vasodilation of superficial vessels, hypotension, or pooling of blood in extremities, results in dizziness, waiting, and nausea
tx for heat syncope
lay athlete down in coo environment, replace fluids
heat cramps
muscle spasms (calf & abdomen) related to excessive water and electrolyte loss (mostly sodium)
common in those who are not acclimatized
prevent with adequate hydration
tx for heat cramp
ingestion of large quantities of fluid, milk prolonged stretching with ice massage
exertional heat exhaustion
occurs from environmental heat stress and strenuous physical exercise
athlete is dehydrated and is unable to sustain adequate cardiac output
mild hyperthermia
tx for exertional heat exhaustion
remove form activity, remove clothing, lie down with legs elected, cooling efforts, rehydrate or IV, monitor heart rate, BP, and core temperature
exertional heatstroke
characterized by CNS abnormalities and potential tissue damage resulting from significantly elevated body temp
can result in death
thermoregulatory mechanism breaks down due to high body temp and inability to dissipate heat
sudden collapse with CNS dysfunction (seizures, confusion, emotional, irrational behavior, decreased mental activity)
rectal temp greater than 104
flushed hot skin, sweating on 75% of the time, shallow fast breathing, rapid/strong pulse, nausea, vomiting, diarrhea, headache, dizziness, weakness, decreased BP and dehydration
tx for heatstroke
whole body cooling, remove clothing, immerse in cool water bath, lower temp to 101, call EMS
malignant hyperthermia
genetically inherited muscular disorder causing hypersensitivity to anesthesia and extreme exercise in hot environments
muscle temperature increases before core temp - causes symptoms similar to heat stroke
complains of muscle pain, rectal temp above 101 for a bit after exercise
should not exercise in heat/humidity
acute exertional rhabdomyolysis
sudden catabolic destruction and degeneration of skeletal muscle accompanied by leakage of myoglobin and muscle enzymes into the vascular system
occurs in hot humid environments in health ppl
grdual onset of muscle weakness, swelling, pain, dark urine, renal dysfunction,
could cause death
exertional hyponatremia
involving a fluid/electrolyte disorder that results in an abnormally low concentration of sodium in the blood
caused by hyper hydration or lack of sodium in the diet.
worsening headache, nausea, vomiting, swelling of hands and feet, lethargy, apathy or agitation, low blood sodium (
dehydration defined as
loss of 2% or more of body weight
CHO to water ratio for quickest fluid absorption
14 g CHO/8 oz of water
why is water a poor dehydrator for athletes?
turns off thirst mechanism
turns on kidneys prematurely
fluid loss in urine is quicker than when drinking sports drink
individuals susceptible to heat illness
large muscle mass overweight males over females poor fitness levels, history of heat illness febrile condition
hypothermia
cold conditions - not enough layers
damp or wet conditoins
50% heat loss through head and neck
20% heat loss is through evaporation (skin and respiration)
shivering ceases at what temp
what core temp implies death is imminent
> 107, 77-85 degrees farenheit
for sport in temp below 32 degrees: how should the athlete dress
a layer of protective clothing added for every 5 mph of wind
frost nip
commonly occurs when there is a high wind, severe cold, or both.
affects ears, nose, cheeks, chin, fingers and toes
skin is firm and cold
painless areas that may peel/blister
tx for frost nip
sustained pressure
no rubbing
blowing hot breath
place fingers in armpits
frost bite types
chillblains, superficial frostbite, deep frostbite
chill blains
prolonged and constant exposure to cold for many hours.
redness, tingling, swelling, and pain in toes and fingers
usually causes by peripheral circulation issues
superficial frostbite
only the skin and subQ tissue. skin is pale, hard, cold, and waxy. underlying deeper tissues will yield to pressure.
deep frostbite
deep tissues frozen,
medical emergency
requires rapid rewarming
injury can become gangrenous
increased altitude can cause
decreased oxygen uptake
4-7% decrease in performance
hyperventilation
fewer saturated RBC available
acute mountain sickness
headache, nausea, vomiting, sleep disturbance, dyspnea (unpleasant breathing) for 3 days
tissue disruption in the brain that affects Na/K+ balance (excess fluid retention in cells)
pulmonary edema
lungs accumulate a small amount of fluid with in alveolar walls
dyspnea, cough, headache, weakness, unconsciousness
pulmonary edema tx
move to lower altitude ASAP, give oxygen
sickle-cell trait and altitude
abnormality of RBC and Hb content
cells clump when abnormal Hb become deoxygenated
can cause enlarged spleen, may rupture
SPF of 6 means
can be exposed to UV light 6x longer than w/o sunscreen before the skin will turn red
flash to bang method
count # seconds between lightning and thunder and divide by 5
see it - flea it
see it, must allow 30 min pass free of lightning before returning to play.
30 min restarts at every proceeding strike
Photochemical haze
nitrogen dioxide and stagnant air that are acted on by sunlight to produce ozone
ozone affects?
increased work output.
SOB, coughing, chest tightness, pain during deep breathing, nausea, eye irritation, fatigue, lung irritation, an lowered resistance to lung infection
asthmatics are at greater risk
smog
produced by combination of carbon monoxide and sulphur dioxide
circadian dysrhythmia
jet lag - desynchronization of the athlete’s biological and biophysical time clock
circadian rhythm
cyclical mechanisms follow a pattern and adapt at varying rates to time change
adapt to jet lag faster flying…
westard
avoid jet lag
hydrate, go bed and wake up an hour earlier,
symptoms of jet lag
fatigue, headache, problems with digestion, changes in BP, heart rate, hormonal release, endocrine secretions, and bowel habits
turf vs grass
it is believed more injuries occur on turf as turf may lose its absorbent shock abilities with age.
no scientific evidence
resilient infill turn made of polyethylene and polypropylene yarns that sit on base of sand or rubber pellets or both
