Lesson 12: Hypothermia

Objectives Describe mechanisms of heat loss Define hypothermia List signs and symptoms Demonstrate emergency treatment for mild to severe hypothermia Describe situations requiring evacuation Describe methods for prevention

Myth or Reality? True or False? 70F or below describes “cold” water A living body always produces heat Hypothermia is contagious, if one person has it, all should be treated A patient with severe hypothermia complains of being cold Wet clothing from rain/sweat can contribute to hypothermia

Key Points Humans maintain normal temperature by: Heat is shed by Heat generated by metabolism Heat gained by outside source (fire/sun) Muscular activity, shivering/exercise Heat is shed by Radiation from skin Conduction via contact with cold surfaces Convection: movement of air over skin Evaporation of moisture from skin respiration

Key Points Normal core temperature is 98.6F Hypothermia occurs if core drops to point where muscle or brain function impaired Hypothermia may be mild to severe Does not have to be “cold” to become hypothermic

Signs/Symptoms for Mild Hypothermia Shivering “umbles” Inability to perform tasks: “fumbles” Confusion, apathy, sluggish, “grumbles” Slurred speech, “mumbles” Altered gait, “stumbles”

Signs/Symptoms for Moderate Hypothermia Worsening of the “umbles” Uncontrollable or violent shivering Confusion or unusual behavior Impaired judgment

Care for Mild to Moderate Hypothermia Ways to warm up someone Change environment Replace wet clothes Move out of wind and cold into a sheltered area Cover all exposed skin Drink/eat simple carbohydrates. Digestion produces internal heat. Do not driver caffeine/alcohol Insulate from ground

Care for Mild to Moderate Hypothermia Bundle in dry insulation Snuggle with warm person Place hot water bottle or chemical heat packs near patients heart and in armpits If patient can exercise, encourage it to produce heat Fluids are more important than solids Warm sweet drink best Even cold drinks better than no fluids

Care for Mild to Moderate Hypothermia If patient goes to sleep, wake periodically to check condition Patient with moderate hypothermia may “think” they are not cold. Watch for altered mental state/judgment If patient can still move adequately, may resume activities after initial care Wait until patient returns to normal perform preceeding

Signs/Symptoms of Severe Hypthermia Shivering stops Muscle rigidity increases Mental state worsens, stupor to coma State of awareness: semi-conscious to unconscious Pulse and respiration rate decrease, may be difficult to detect Complaining stops

Care for Severe Hypothermia Handle gently, roughness can overload cold heart and stop it If not breathing, perform rescue breathing (CPR) for at least 3 min prior to moving Start to warm patient, same as mild to moderate hypothermia Warming too quickly/too much movement may cause cold blood from extremities to rush to heart and stop it

Care for Severe Hypothermia Use hypothermia wrap, vapor barrier to trap any heat inside Wrap patient in tent fly, sheet of plastic, etc Leave face exposed and monitor airway/breathing Do not force food/liquids Care for patient even if they appear dead Call for help immediately, do not evac unless it can be done gently

Guidelines for Evacuation Mild and Moderate cases likely will recover and may remain in the field GO FAST for severe cases. Evacuate with extreme care to not jostle the patient

Preventing Hypothermia Far easier to maintain core temp than to regain it Prevent heat loss Terminate exposure Detect early warning signs and treat early Replace wet clothes quickly What you wear has major effect on preventing hypothermia

Preventing Hypothermia Types of Clothing for Preventing Hypothermia silk, wool, and synthetics designed to wick moisture away Layers of clothing help you stay dry Layers help regulate temperature better Hats prevent heat loss through head (major source of loss) If feet cold, put on a hat Protect hands and feet, change socks often Rain gear/water proof boots

Preventing Hypothermia Avoid Cotton, traps moisture Maintain hydration Avoid alcohol and caffeine Eat regularly, especially carbs Stay active but don’t over exert Know the weather, be prepared for changing conditions

Preventing Hypothermia Terminate exposure early If you can’t stay warm/dry, get out of wind and rain Set up camp early, before you are exhausted Early Detection Watch yourself and others for behavior or exposure that can lead to hypothermia Care for signs early, monitor others if one has symptoms Being cold affects judgment, believe signs not patient