Cold to the Core: How to Spot & Treat Severe Hypothermia Fast

When the temperature drops, the risk  of hypothermia rises, and as urgent care clinicians, we need to be ready to recognize and treat this potentially life-threatening condition. But before jumping into severe hypothermia treatment, let’s start with the basics—how do we identify hypothermia symptoms, and what should we be looking for in our patients? 

Always Consider Hypothermia

The first step in recognizing hypothermia is simply thinking about it. 

It’s easy to assume this only happens in freezing conditions, but hypothermia doesn’t always require snow and ice. A core temperature of 95°F (35°C) or lower is all it takes for a diagnosis, and patients can develop it even in cool, wet, or windy weather.

Key Takeaway: Key takeaway: A forehead or oral thermometer won’t cut it. For accurate diagnosis, you need a rectal temperature. Those quick-check thermometers in urgent care are unreliable when identifying hypothermia symptoms, so don’t rely on them—get the real number.

Who’s at Risk? It’s Not Just the Cold Outdoors

Some patient populations are more susceptible to hypothermia, even in conditions that don’t seem extreme:

• Elderly Individuals: Reduced thermoregulation and underlying medical conditions make them more vulnerable.
• Homeless Populations: Limited access to adequate shelter or clothing during cold weather increases risk of hypothermia.
• Children and Infants: Due to their smaller body size and higher surface-area-to-mass ratio, children and infants are at increased risk for rapid heat loss.
• Individuals with Chronic Illnesses: Diabetes, hypothyroidism, and alcohol use disorder can impair thermoregulation.
• Medications and Alcohol: Sedatives, antipsychotics, and alcohol can interfere with the body's ability to generate and retain heat.

Classification of Hypothermia: Mild, Moderate, or Severe?

Once you've identified hypothermia, it’s helpful to understand its severity. Here’s a quick rundown of how to classify it:

Why does this matter? Patients may stop shivering before they reach severe hypothermia—don’t wait for obvious signs before acting.

Should Every Hypothermic Patient Go to the ED?

In short: Yes. 

Even mild hypothermia symptoms can escalate quickly, and severe hypothermia treatment often requires interventions that go beyond the scope of urgent care. The moment you suspect hypothermia, call EMS. These patients need controlled rewarming and cardiac monitoring that urgent care simply can’t provide.

This is a "direct report to the ED" kind of case—don’t delay transport.

The First 5 Minutes: Critical Action Steps

Once you’ve identified hypothermia, it’s time to act. Here’s how to approach it while awaiting EMS transport:

Passive External Rewarming

• Remove cold or wet clothing (critical first step!).
• Increase room temperature and cover the patient with dry, warm blankets.

• Apply warm blankets, heat packs, or other external heat sources.
• Avoid direct heat sources like heating pads, as these can cause burns on cold, numb skin.

Active internal rewarming 

While you won’t typically perform this in urgent care, setting up EMS or the ED to start warming IV fluids can be incredibly helpful.

Watch for these critical issues

• Check the patient's glucose levels: Hypoglycemia can exacerbate the effects of hypothermia. Additionally, while an ECG might be considered, it won’t change your immediate management, but there’s a fun teaching point here that could come in handy.

• Be Gentle: Hypothermic patients can be very sensitive to movement due to the destabilization of their cardiac membranes - even moving from your bed to the EMS stretcher can precipitate a malignant ventricular arrhythmia like VF. 

What’s That on the ECG? Recognizing the J Wave 

In severe hypothermia, you might see something unique on the ECG: the Osborn wave (also known as “J wave”).

This is a positive deflection at the J-point, where the QRS complex meets the ST segment. It’s not a STEMI, but it’s a hallmark of severe hypothermia. Don’t let it distract you—focus on warming the patient and getting them to definitive care.

Hypothermia Recognition and Action Steps

• Think Hypothermia First: It’s not just for extreme cold; consider it in elderly patients, altered mental status cases, and prolonged exposure scenarios.
• Get a Core Temperature: Don’t trust forehead or oral thermometers.
• Warm the Patient Immediately: Remove wet clothing, add blankets, and start passive rewarming.
• Call EMS Early: Even if you’re stabilizing the patient, they need the ED for full severe hypothermia treatment.
• Be Gentle: Avoid sudden movements to prevent cardiac arrhythmias.

Hypothermia is more common than we think, but early recognition and interaction can be the difference between life and death. Stay sharp, stay prepared, and never underestimate the cold.