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Hypothermia: the signs, and rewarming without killing them

Hypothermiahypothermia Losing body heat faster than you can make it. Shivering first, then confusion and a false feeling of warmth, then unconsciousness. Wet and wind do it even above freezing. is losing heat faster than your body makes it. It does not need a blizzard; wet clothes, wind and water above freezing do it. The manuals agree on the signs, and they are careful about rewarmingrewarming Warming a person back up after they got too cold. Done slowly and from the core outward., because warming a cold person too fast can stop the heart.

Step by step

1. Causes: general exposure, a sudden wetting such as falling into a lake, wind, and wet-cold conditions well above freezing. Exhaustion, too little food, dehydrationdehydration Your body has less water than it needs. Thirst, dark urine, headache, tiredness and dizziness are the early signs. and alcohol all make it more likely. Wet-cold means damp, rainy weather that is cool rather than freezing, and it is one of the most common ways people get hypothermia. The manuals also name being worn out, not eating, not drinking enough, and alcohol.

   

2. It starts with shivering. The shivering becomes uncontrollable, and as the core drops to about 95 to 90 degrees F (35 to 32 C) comes sluggish thinking, irrational reasoning, slurred speech, stiff clumsy movements, and a false feeling of warmth. At 90 to 86 F (32 to 30 C) and below: muscle rigidity, unconsciousnessconscious Conscious means awake and able to respond. Unconscious means they cannot be woken. Semiconscious is in between. and barely detectable signs of life. Below 77 F (25 C) death is almost certain. The core is the temperature deep inside, not the skin. That sudden feeling of warmth is a sign the person is getting worse, not better. The first aid manual adds that as it gets worse, the eyes look glassy and breathing turns slow and shallow.

3. Act at the first stage. The recovery manual's marker is intense shivering with trouble doing complex tasks. By the time thinking is sluggish, the person cannot save themselves. A complex task is anything that takes fine control, like working a zipper or tying a knot. Watch each other: the manuals say the buddy system is critical, because the person getting cold is often the last to notice.

4. Get them out of the cold. Strip wet clothing at once, put on dry clothing, bundle them into a sleeping bag, cover the top of the head, and insulateinsulation Anything that traps still air and slows heat from leaving: dry leaves, pine needles, snow, wool, a puffy jacket. above and below. Build a shelter if there is none. Wet clothes keep pulling heat away, so they come off first. Cover the head and put insulation under the person as well as on top, so the cold ground does not draw out their heat. You did it right when they are in dry layers, out of the wind and off the ground.

   

5. Rewarm the whole body evenly and without delay. Warm the core before the limbs: warm canteens or heat packs at the groin, armpits and neck, taking care not to burn the skin; a campfire; another person's body heat. Focus on the chest, belly, groin, armpits and neck before the hands and feet. Wrap warm bottles or hot rocks in cloth first. The survival manual also lists a fire on either side of the person.

6. Skin to skin in a sleeping bag with a warm person is a survival technique the manuals allow, with a warning: the warm person can become hypothermic too if they stay in too long. In the survival manual's method, both people are undressed inside a warmed sleeping bag. Watch the helper too, and switch helpers if they start to get cold.

7. If the person is conscious, give hot, sweetened fluids. Honey or dextrosedextrose A simple sugar the body uses fast. Sold as glucose tablets or gel. are best, then sugar, cocoa or similar. Never force an unconscious or semiconscious person to drink; they can choke. Calories are the body's fuelfuel wood Dead wood from finger to wrist thick that keeps the fire going once the kindling has caught. for making heat, which is why sugar helps. A person who is not fully awake can choke on a drink.

8. The two dangers are rewarming too fast, which can cause heart failure, and after dropafter drop A cold person’s core gets colder for a while after rescue, as cold blood from the arms and legs flows back to the heart., when cold blood from the limbs returns to the core. Handle the person gently. A warm bath is a hospital treatment only. After drop means the core gets colder again during rewarming, because cold blood from the arms and legs flows back to the middle. The survival manual says warming the core first lessens it. Lift and move the person gently; the first aid manual says walking can make the circulation problems worse.

9. Severe hypothermia (unconscious, weak pulsepulse The beat of the heart you can feel in the wrist or neck. Count beats for 15 seconds and multiply by 4 for beats per minute., core around 90 F or below): do not try to rewarm in the field. Stabilize the temperature, stop further heat loss, handle gently, start mouth-to-mouth if breathing stops, and get them to medical care by litter, not on foot. A blanket alone is not enough, because they cannot make their own heat. Call 911 if you can. Rewarming a person this cold in the field is dangerous, so your job is to stop more heat loss, keep them still and gentle, and get help. Rescue breathing starts if breathing stops or becomes irregular or very shallow.

10. Prevent it: dress for the conditions, eat and rest, test ice before crossing, never travel alone, and leave your route and return time with someone before you go. Leaving your route and return time with someone means that if you do not come back, people know where to look. The first aid manual also says to carry enough extra clothing and food for an unexpected change in the weather.

Tips from survival instructors

• Umbles are a warning sign: someone who stumbles, mumbles, fumbles and grumbles is getting too cold.
• Get the person out of wet clothes and wind first, then warm the chest, armpits and neck, not the arms and legs.

Quick check

Someone has fallen through ice. What comes first?

• A hot bath
• Strip the wet clothes, get them dry, covered and out of the wind
• Make them walk to warm up

Show the answer

Strip the wet clothes, get them dry, covered and out of the wind

Before you rely on thisA learning tool, not a replacement for training. In an emergency, call 911.

Sources

• US Army Survival Manual, pages 46 and 193 to 194 (hypothermia, rewarming, after drop)
• Army First Aid Manual, pages 158 to 160 (hypothermia signs, treatment, prevention)
• Military Survival and Rescue Guide, pages 50 to 51 (hypothermia stages, protect the victim)
• US Army Survival Manual, pages 22, 33, 46 and 192 to 194 (calories, warming a shock victim, hypothermia definition and stages, rewarming, after drop)
• Army First Aid Manual, pages 158 to 160 (hypothermia causes, signs, treatment, severe hypothermia, prevention)
• Military Survival and Rescue Guide, pages 50 to 51 (stages of hypothermia, protecting and rewarming the victim)

Photo credits

Photo: U.S. Marine Corps photo by Lance Cpl. Franco Lewis, Public Domain, sourcePhoto: Smack (talk), Public Domain, source

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