extremes of heat Flashcards
What is a ‘normal’ body temperature ?
What is a ‘normal’ body temperature ? 37 degrees.
Normal range of 35.8-38.2 degrees.
So what mechanisms do we have to maintain a normal body temperature ?
HYPOTHALAMUS
Receives sensory information from peripheral & central thermoreceptors in Core (organs in skull, thorax & abdo) and Shell (skin).
Heat generated or lost is controlled by flow of blood to ‘shell’.
Heat Promotion V Heat Loss
think heat
Constrict blood vessels Shivering Metabolic rate Clothing Hot drinks Physical activity
Heat Promotion V Heat Loss
think heat loss
Dilates blood vessels Radiation Conduction Convection Evaporation
Hypothermia
Core temp of less than 35 degrees
Mild = 32-35 degrees
Moderate = 28 – 32 degrees
Severe = less than 28 degrees
Hypothermia
** it can be difficult to record accurate temp with low temps ** Suspect it in : Older pts (over 80yrs) Children Hypothyroidism Intoxication Drowning Patients with exhaustion Injured or immobile Decreased level of consciousness
Hypothermia 5 stages what are they
Move through 5 stages : Conscious & shivering, Decreased level of consciousness & not shivering, Unconscious, Not breathing, Death due to irreversible hypothermia.
Management of hypothermia
Management : Prevent further heat loss.
Remove to warm environment
Remove wet clothes
Use blanket before foil blanket
Do not give alcohol
Do not rub skin – peripheral vasodilation
Avoid rough handling – arrhythmias, cardiac arrest
IV fluids should be warmed
Manage patients with reduced level of consciousness horizontally.
Heat Stress, Exhaustion & Stroke occurs why
Occurs as result of external factors eg sun, or internal factors eg drugs, exercise.
Heat Stress = mild form.
Heat Stress = mild form.
Normal Temp or mild elevation
Heat oedema – swelling of feet & ankles
Heat syncope – vasodilation causing hypotension
Heat cramps – muscle cramps due to depletion of salts
Heat Exhaustion = more severe
Heat Exhaustion = more severe. Symptoms due to fluid loss and electrolyte imbalance.
Systematic reaction
Core temp >37 degrees, <40 degrees
Headache, dizziness, nausea, vomiting, tachycardia, hypotension, sweating, muscle pain, weakness, cramps
Can progress quickly to heat stroke
Heat Stroke = systemic inflammatory response,
Heat Stroke = systemic inflammatory response,
Non-exertional = high external temps/humidity = young, elderly, chronically ill
Exertional = excess heat production = active groups ie athletes, military
Core temp 40 degrees or more Hot dry skin (sweating can still be present) Extreme fatigue, headache, vomiting, fainting, facial flushing, vomiting, diarrhoea Arrhythmias & hypotension Respiratory distress Liver & kidney failure
Management of heat
Heat Stress, Exhaustion & Stroke
Management Remove from heat source Passively cool, loosen tight clothing, put in shade or air conditioned area Oral isotonic fluid replacement Elevate oedematous extremities. Cold-water immersion/spray Fanning Consider ice packs but not directly to skin.
