Chapter 6: Environmental Considerations

Question 1

Define Hyperthermia

Answer 1

Elevated body temp.

Question 2

5 ways heat can be gained or lost

Answer 2

1) metabolic heat production
2) conductive heat exchange
3) convective heat exchange
4) radiant heat exchange
5) evaporative heat loss

Question 3

Define Metabolic Heat Production

Answer 3

Heat produced by normal metabolic function.

. Increase in activity increases metabolic function and therefor amount of heat produced

Question 4

Define conductive heat exchange

Answer 4

A heat loss or gain as a result of physical contact with other objects

Question 5

Define convective heat exchange

Answer 5

heat loss or gain when a mass of either air or water moves around an individual.

Question 6

Define convective heat exchange

Answer 6

heat loss or gain when a mass of either air or water moves around an individual.
. Removes heat from the body’s surface

Question 7

Define radiant heat exchange

Answer 7

dilation of superficial blood vessels allowing heat to dissipate through the skin.
. can gain heat through radiant exchange from the sun

Question 8

Define evaporative heat loss

Answer 8

Sweat evaporates taking heat w/ it.

. sweating doesn’t cause heat loss, it must evaporate off the skin.

Question 9

How does humidity affect evaporative heat loss?

Answer 9

Increased air humidity causes a decrease in sweat evaporation.
. heat loss is severely impaired when relative humidity is 65% and virtually stops at 75%

Question 10

Factors affecting sweat rates

Answer 10

height and weight 
acclimatization 
fitness levels 
hydration status 
environmental conditions 
clothing 
intensity & duration of activity 
heredity

Question 11

S&S of mild dehydration

Answer 11

thirst / dry mouth
headache
dixxiness 
irritability 
lethargy
excessive fatigue
cramps

Question 12

an adult doing minimal activity needs ___L of water/day

Answer 12

2.5 L

Question 13

Average sweat loss during an hour of exercise is ____L

Answer 13

1.5 L

Question 14

Gradual acclimatization to avoid heat stress should occur over ____ days

Answer 14

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

Question 15

Individuals susceptible to heat stress

Answer 15

young & elderly 
over weight 
ppl w/ poor fitness levels 
ppl w/ history of heat illness 
ppl w/ fever
ppl w/ sickle cell trait

Question 16

what does WBGT stand for and what does it do

Answer 16

Wet Bulb Globe Temperature

Question 16

what does WBGT stand for and what does it do

Answer 16

Wet Bulb Globe Temperature

. Objective means of determining heat index

Question 17

what is the WBGT calculation

Answer 17

WBGT = 0.1 X DBT + 0.7 X WBT + GT X 0.2

. DBT = Dry bulb temp (mercury thermometer)
. GT = Globe temp (measures sun’s radiation)

Question 18

What is the WBGT calculation if there is no GT reading?

Answer 18

WBGT = 0.3 x DBT +0.7 X WBT

Question 19

What is heat rash?

Answer 19

red raised rash that prickles/tingles during sweating

usually occurs when skin is continually wet

Question 20

What is heat syncope / heat collapse

Answer 20

rapid physical fatigue during over exposure to heat

. caused by peripheral vasodilation of superficial vessels and pooling of blood in the extremities

Question 21

Signs of heat syncope and Tx

Answer 21

. dizziness, fainting and nausea

. lay pt in a cool environment, elevate legs and replace fluids

Question 22

What are Exertional Heat Cramps

Answer 22

. Painful muscle spasms (calf and abdomen)

. loss of water and electrolytes causing an imbalance

Question 23

Tx of Exertional Heat Cramps

Answer 23

. Sports drinks

. mild, prolonged stretching w/ ice massage

Question 24

What is Exertional Heat Exhaustion

Answer 24

. Results from dehydration, heat stress, & exercise . unable to sustain cardiac output . rectal temp of less than 104 . no CNS dysfunction

Question 25

S&S of Exertional heat exhaustion

Answer 25

``` . no CNS impairment . pale skin . profuse sweating . stomach cramps . vomiting . diarrhea . headache . persistant MUS cramps . dizziness . loss of coordination ```

Question 26

Tx of Exertional heat exhaustion

Answer 26

. Immediately remove from play and put in shade . remove excessive clothing . lay down and elevate legs . cool until internal temp of 101 . rehydrate w/ sports drinks (if not nauseous or vomiting) . transport to ER if there is no rapid improvement

Question 27

what is Exertional Heatstroke

Answer 27

. CNS abnormalities . potential tissue damage from increase body temp . can occur suddenly w/out warning . rectal temp is 104 and up

Question 28

S&S of Exertional Heatstroke

Answer 28

``` . sudden collapse w/ CNS dysfunction . altered consciousness, seizures, confusion, emotional instability, irrational behaviour and/or decreased mental acuity . flushed, hot, and dry skin . shallow, fast breathing . rapid, strong pulse . Nausea &/or vomiting . diarrhea . headache . dizziness . weakness . low BP . dehydration ```

Question 29

Tx of exertional heatstroke

Answer 29

. lower body temp ASAP . remove clothing, cold water immersion or sponge, fans, ice packs . activate EAP . pt should avoid exercise for 1 week, and gradually RTP after being fully cleared by Dr.

Question 30

What is Malignant Hyperthermia

Answer 30

. rare genetic muscle disorder . causes hypersensitivity to anesthesia & extreme exercise in hot environments . muscle temp increases to the point of tissue breakdown .products of breakdown may damage kidneys and cause acute renal failure . pt complains of muscle P after exercise, rectal temp remains elevated 10-15 min post exercise . need biopsy for Dx

Question 31

What is Acute Exertional Rhabdomyolysis

Answer 31

. sudden destruction of skeletal muscle w/ leakage of myoglobin and muscle enzymes into blood. . gradual onset of muscle weakness, swelling, P, darkened urine & renal dysfunction . associated w/ ppl w/ sickle cell trait

Question 32

What is Exertional Hyponatremia

Answer 32

``` . Low sodium levels . caused by ingesting too many fluids S&S: . worsening headache, nausea/vomiting, swelling of hands and feet, lethargy, apathy, agitation . very low amounts can compromise CNS ```

Question 33

what is the average body temp

Answer 33

98.6 F or 37 C

Question 34

at what body temp does shivering stop

Answer 34

85-90 F 29.4-32.2 C

Question 35

death is imminent at what core body temp

Answer 35

77-85 F 25-29 F

Question 36

What is frost nip

Answer 36

. affects ears, nose, cheeks, chin, fingers & toes . occurs with high wind or severe cold . skin is firm, w/ cold painless areas . skin may peel or blister in 24-72hrs

Question 37

Tx of frost nip

Answer 37

. firm sustained pressure . blowing hot air on spot . placing fingers in armpits . NO RUBBING

Question 38

What are the 3 types of frostbite

Answer 38

1) chilblains 2) superficial frostbite 3) deep frostbite

Question 39

Chilblans

Answer 39

. prolonged exposure to cold (many hrs) . skin redness, swelling, tingling and P in fingers and toes . problems w/ peripheral circulation

Question 40

Superficial Frostbite

Answer 40

. involves only the skin & subcutaneous tissue . skin is pale, hard, cold & waxy . rewarm by immersing area in warm water

Question 41

Deep Frostbite

Answer 41

. tissues are frozen . immediate hospitalization . tissue is first cold, hard, pale/white & numb . after rewarming is blotchy, swollen and extremely painful . rewarm w/ hot drinks, heating pads and hot water bottles . tissue may become gangrenous