Chapter 6: Environmental Considerations Flashcards
Define Hyperthermia
Elevated body temp.
5 ways heat can be gained or lost
1) metabolic heat production
2) conductive heat exchange
3) convective heat exchange
4) radiant heat exchange
5) evaporative heat loss
Define Metabolic Heat Production
Heat produced by normal metabolic function.
. Increase in activity increases metabolic function and therefor amount of heat produced
Define conductive heat exchange
A heat loss or gain as a result of physical contact with other objects
Define convective heat exchange
heat loss or gain when a mass of either air or water moves around an individual.
Define convective heat exchange
heat loss or gain when a mass of either air or water moves around an individual.
. Removes heat from the body’s surface
Define radiant heat exchange
dilation of superficial blood vessels allowing heat to dissipate through the skin.
. can gain heat through radiant exchange from the sun
Define evaporative heat loss
Sweat evaporates taking heat w/ it.
. sweating doesn’t cause heat loss, it must evaporate off the skin.
How does humidity affect evaporative heat loss?
Increased air humidity causes a decrease in sweat evaporation.
. heat loss is severely impaired when relative humidity is 65% and virtually stops at 75%
Factors affecting sweat rates
height and weight acclimatization fitness levels hydration status environmental conditions clothing intensity & duration of activity heredity
S&S of mild dehydration
thirst / dry mouth headache dixxiness irritability lethargy excessive fatigue cramps
an adult doing minimal activity needs ___L of water/day
2.5 L
Average sweat loss during an hour of exercise is ____L
1.5 L
Gradual acclimatization to avoid heat stress should occur over ____ days
7-10 Days
. days 1-6 80% acclimatization w/ 2hr practices in the mornings and evenings
. sessions broken down into 20min work, 20 min rest
Individuals susceptible to heat stress
young & elderly over weight ppl w/ poor fitness levels ppl w/ history of heat illness ppl w/ fever ppl w/ sickle cell trait
what does WBGT stand for and what does it do
Wet Bulb Globe Temperature