Environmental Emergencies Flashcards
What does the Hypothalamus do?
Regulates body temperature
- uses central (aortic arch/ carotids) and peripheral chemoreceptors
Thermal Gradient
Warm temps will always move towards cooler temps
- Gain heat when it is warm outside
- Lose heat when it is cold outside
How to regulate body temperature (2 ways)
- Behavioral
- Physiologic
Behavioral way to regulate body temp
Conscious effort to change the temp sensation
- COLD: Move to warm area, add clothing
- HOT: Remove clothing, move to air conditioning
Physiologic way to regulate body temp
Body’s response to change in temp
- COLD: Shivering, constricting of blood vessels
- HOT: Sweating, dilating of blood vessels
Heat Production: how does the body produce heat?
- Body produces heat mainly through metabolism
- Shivering increase heat production
- stops when core temp drops below 90
Heat Conservation: how does the body preserve heat?
Peripheral Vasoconstriction:
- Shunts warm blood to vital organs
Piloerection:
- Goose bumps
- Traps warm air at skin surface
How does the body cool itself off?
Skin:
- Vasodilation: warm blood to skin surface
- Sweating: Evaporation
Cardiovascular system:
- increased in heart rate and strength of contraction
Respiration:
- Eliminated heat through exhalation
How heat can be lost or gained
- Radiation
- Convection
- Conduction
- Evaporation
- Respiration
Radiation
Transfer heat from one surface to another without direct contact
Convection
Body heat lost to surrounding air, which becomes warmer, leaving skin cooler
Conduction
Heat lost through direct physical touch
Evaporation
Sweating or wet skin evaporates into air
Respiration
Warmed air is exhaled and cool air is inhaled
Hypothermia (Predisposing factors)
Young:
- LG surface area of skin, shivering mechanism not fully developed, less body fat, less adaptive behaviors
Old:
- Loss in metabolism, poor vessel constriction
Medical Conditions:
-Shock, TBI/ Stroke, Burns, etc
- Decrease body’s ability to regulate temperature
- Decrease body ability to clot
Drugs/ Med:
- May impair heat generating or heat conserving properties
- Duration of exposure, clothing, activity level
STAGES of Hypothermia
- Mild
- Moderate
- Severe
MILD Hypothermia
- 95- 91.4
- Skin cold to touch
- Confusion (inadequate perfusion)
- Shivering ceases around 90 degrees
- Heart rate slows
MODERATE Hypothermia
- 89.6- 85.2
- Coma
- Hypotension
- Bradycardia
- Slow breathing
SEVERE Hypothermia
- 82.4- 71.6
- Cyanosis
- Unresponsive
- Irregular Pulses
- Cardiac Arrest possible
Frostbite
- Freezing of body tissues
- Usually to exposed tissues
- Hands
- Feet
- Ears, nose, cheeks
Superficial Frostbite
- Loss of sensation, cold feeling
- Usually tingles when rewarmed
Deep Frostbite
- Skin and tissue frozen
- May have blisters
- Can result in tissue loss
Cold Emergency Treatment
- Remove from environment/ prevent heat loss
- Remove wet clothing
- Handle gently
Rewarming (2)
-Passive (shivering patient)
- Active (patient has stopped shivering because internal body temp is below 90)
