EMS: Hypothermia: The Ins and Outs of Cold Emergencies

'Tis the season for chilly temperatures. Now, I love this time of year—my Norwegian ancestors would be proud of my cold weather tolerance—but let’s be real: Cold is a challenge for everyone, and it can be downright dangerous. It slows cognition, clouds decision-making and can cause nasty complications.

If we understand and respect the cold, we can live happily alongside it. That said, for those who get caught off guard by Elsa’s wrath (yes, I have kids, and, yes, I sing the songs from “Frozen”), the cold can lead to serious trouble.

Hypothermia: the basics
Hypothermia occurs when the body gets too cold because of external influences. It doesn’t take much for our internal temperature to drop below the normal 98.6 degrees Fahrenheit (37 degrees Celsius), and the lower that we go, the more dangerous that it gets.

Hypothermia is classified three ways: mild (89–95 degrees F), moderate (82–89 degrees F) or severe (below 82 degrees F).

The key indicator of hypothermia is mental status—confusion, lethargy and, eventually, unresponsiveness—as temperature drops.

The body tries to protect itself from the cold by shivering to produce heat and by reducing blood flow to nonessential areas, known as peripheral shunting. This process prioritizes vital organs, to keep them warm and functional. From mild to severe hypothermia, patients will progress from shivering to not shivering (which is a bad sign) as their body’s capability to generate heat diminishes. Motor skills also decline, from losing fine motor control to complete immobility.

Treatment
Treatment starts with one critical action: Get the patient to a warm environment—whether that’s an ambulance or indoors. If applicable, remove wet clothing. The treatment approach depends on the severity of hypothermia:

• Mild hypothermia: Passive rewarming is sufficient. Blankets and a heater are your best friends here.
• Moderate hypothermia: Active external rewarming is necessary. Hot water bottles or covered hot packs should be applied to junctional areas (neck, armpits, groin) and the chest. Hypothermia management kits, such as North American Rescue’s Hypothermia Prevention and Management Kit, work great. Just follow the directions. One key point: Never place hot objects directly onto the skin. Hypothermic patients might not feel burns, so always keep something between the skin and heat sources.
• Severe hypothermia: Active internal rewarming is needed if available and within scope. This may include warmed IV fluids (96–100 degrees F) or transferring the patient to a facility that can provide extracorporeal membrane oxygenation (ECMO). ECMO involves removing the blood, warming and oxygenating it, then returning it to the body—essentially doing the heart and lung’s job while they rest.

Special considerations
Handling hypothermic patients requires care. They are prone to arrhythmias, and rough handling can push them into cardiac arrest. There’s an old saying: “No one is dead until they’re warm and dead.” This applies strongly to hypothermia cases, particularly during resuscitation. If the initial defibrillation is unsuccessful, wait until the core temperature is at least 86 degrees F (30 degrees C) before you try to defibrillate again. Measuring core temperature is best done with a rectal thermometer.

Keep in mind, hypothermic patients often require longer CPR than usual. Hypothermia slows the body’s metabolism, which reduces oxygen requirements, which is why people can survive prolonged arrests in cold water or hypothermic conditions. It gives the brain and organs a better chance of recovery.

Six keys
The moral of the story: Get them out of the cold, remove wet clothes, warm them up, get them to the right facility and work that code longer than usual—and be very gentle in handling. Following these steps gives your patient a fighting chance—maybe enough to brave the cold again someday.