1. Lesson 13: Heat Related Illnesses

2. Objectives Define heat exhaustion, heat stroke, and hyponatremia
Describe prevention techniques
List signs/symptoms for heat related illnesses
Describe emergency treatment
Describe situations that require emergency evacuation

3. Heat Related Illnesses Overview
Range of problems associated with very warm to hot air temps
Other factors involved
Humidity
Being overweight/out of shape
Very young or very old
Unaccustomed to heat
Certain drugs such as antihistamines
Continued exercise
dehydration

4. Heat Related Illnesses Overview
Heat exhaustion result of combination of factors
Heat stress
Water/electrolyte loss
Inadequate hydration
Heat stroke when core produces heat faster than it can be dissipated.
Over-exerting or dehydrated
Hyponatremia: low blood sodium level. May be from drinking too much water or failing to eat

5. Preventing Heat Related Illnesses
What can you do to prevent heat related illnesses
Stay well hydrated, consume water prior to exercising and during exercise
Wear baggy, loosely woven clothing to allow evaporation
Keep head covered and face shaded
Keep fit, start slowly
Avoid exercise during hottest part of day
Drugs may increase risk
Rest in shade often

6. Signs/Symptoms for Heat Exhaustion
Sweating
Tiredness and feeling lethargic
Skin appears pale and sweaty or flushed
Headache
Nausea, sometimes vomiting
Muscle cramps
Thirst/decrease urine output
Dizziness
Elevated heart rate
Possible slight increase in core temp

7. Caring for Heat Exhaustion
Stop activity, rest in cool/shady area
Replace lost fluids
Quart of water with pinch salt added. Drink over 20 min period
Do not use salt tablets, too concentrated
Wet down patient
Gently stretch and massage cramped muscles
Allow drowsy patient to sleep
Recovery may take 24 hrs
When patients feels ok, allow to continue

8. Signs/Symptoms for Heat Stroke
Core temperature rising to 105F
Disorientation, bizarre personality changes
Skin turning hot and red, may be dry
Elevated heart and respiratory rate
Headache
seizures

9. Care for Heat Stroke True emergency, rapid cooling is essential
Remove from hot environment
Remove heat retaining clothing
Immerse in cool water or drench in cool/cold water
Concentrate cooling on head and neck
Use cold packs on neck, armpits, groin, hands, feet
Fan patient to increase evaporation

10. Care for Heat Stroke
Monitor patient closely and cease cooling efforts when normal status returns
Give cold water to drink if patient can accept it
Do not give fever reducing drugs
Have patient see health care provider as soon as possible
Keep careful watch on patient since relapses are common

11. Signs/Symptoms for Hyponatremia
Appears to have heat exhaustion but giving more water makes it worse
Also called water intoxication
Looks like heat exhaustion but
Urinated recently and was clear
Claims of having been drinking all day, denies being thirsty
Headache
Weakness and fatigue
Light headedness

12. Signs/Symptoms for Hyponatremia
Muscle cramps
Nausea with/without vomiting
Sweaty skin
Normal core temp
normal/slightly elevated pulse/respiration rate
Increasing level of anxiety
More severe symptoms include disorientation, irritability, combativeness
If untreated can lead to seizures, coma, death

13. Caring for Hyponatremia
Mild to moderate cases can be cared for in the field
Rest in shaded area
Eat salty foods. Do not have them drink anything
If patient is well hydrated restricting fluid intake is harmless
Once patient has normal hunger and thirst and normal urine output, condition is resolved

14. Scenarios
24 yr old, slightly overweight, competing in short distance triathalon. Says he drank 3 – 4 qts water. Stumbling while running up a hill and stops at your first aid station

15. Scenarios
68 yr old woman in excellent condition is working on wilderness survey. She is sweating while carrying camera equipment then becomes confused and vomits

16. Guidelines for Evacuation
GO SLOW for patient who does not fully recover from heat exhaustion or mild hyponatremia
GO FAST for patient with altered mental state due to heat related issues or hyponatremia or experiences seizure