Heat illness

Question 1

Symptoms of Heatstroke

Answer 1

Core temp >40
Vomiting and or  convulsions
Collapsed - coma
Impaired mental and temp regulation function 
Pale and sweaty skin

Question 2

Predisposing factors of Heatstroke

Answer 2

Strenuous exercise in hot/humid environment
No heat acclimation
Poor physical fitness
Can occur in well trained/acclimatised athletes

High risk when wet bulb globe temp exceeds 28• and exercise >75% vo2 max

Question 3

Why does heatstroke occur?

Answer 3

Internal organ tissue
Cell energy systems damaged
Cells membranes damaged
Above 40• disrupts cell volume, metabolism, acid based balanced

Question 4

Treatment for heatstroke

Answer 4

Immediate whole body cooling
Begin and complete onsite before transfer to hospital
Most rapid for cooling - Cold water and ice water immersions
Alternatives - ice water soaked towel to head, trunk and extremities
Ice packs to lower body
Warm air mist - dependant on evaporation so humidity is important

Question 5

Return to exercise after heatstroke

Answer 5

No exercise for minimum 7 days
Physical exam follow up in 1 week
Exercise in cool environment and gradually increase duration and intensity
Heat exposure for 2 weeks to acclimatise and demonstrate heat tolerance

Question 6

Symptoms of heat exhaustion

Answer 6

Rectal temp of ~39•
Mental function and thermoregulation are mildly impaired
Profuse sweating
Tachycardia - high HR, low BP
High cardiac output and respiration rate
Sweaty, pale and ashen

Question 7

Predisposing factors of heat exhaustion

Answer 7

Body mass index > 27kg.m-2
Work hottest months of year
Elevated urine specific gravity
>33•C

Question 8

Why does heat exhaustion occur?

Answer 8

Peripheral vasodilatation

Vaisodialatation induces hypertension

Blood volume pooled in the skin and extremities reduces heat transfer from the core to the body surface and reduces heat loss from skin surface

High air humidity - evaporative cooling is impaired

Question 9

Return after heat exhaustion

Answer 9

24-48 h (mild)

Gradually increase intensity and volume of activity

Neither rest or cooking allows full recovery on the same day

Serious complications are rare

Question 10

What are the symptoms of heat cramps

Answer 10

Muscle group contract causing pain sometimes excruciating

occurs in legs and arms

Question 11

Predisposing factors of heat cramps

Answer 11

Exercise induced muscle fatigue

Body water loss

Large Na+ loss

Long -duration, high-intensity exercise

Question 12

Why do heat cramps occur

Answer 12

Deficit of Na+ levels

Alterations in electrical potentials of nerve and muscle tissues

Intracellular dilution believed to play a part in developing muscle cramps

Question 13

Treatment of heat cramps

Answer 13

Rest

prolonged stretch

Rehydration

oral and NaCL ingestion (food or fluids)

Check for hypohydration

Question 14

Return to exercise after heat cramp

Answer 14

Following rest and fluid replacement

May be associated with heat exhaustion

Question 15

Treatment of heat exhaustion

Answer 15

Shaded/ conditioned area

Remove excess clothing

Supine position with legs elevated

Measure HR, BP, respiratory rate, rectal temp and CNS status closely

Leg elevation oral fluids and rest

Not always involve elevated core temp