Disclaimer: The information in this article is for educational purposes only and is not a substitute for professional medical training. Take a Wilderness First Aid course from a certified instructor. These courses save lives. This article does not.
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Third rifle season in unit 76, up above Sargents in the Cochetopa Hills of Colorado. My buddy Travis and I had been glassing a north-facing basin since 5:30 AM, sitting mostly still in about 18°F air with a wind that pushed the real feel down around zero. We’d layered up — or so we thought. Travis had cotton long johns under his hunting pants because he’d grabbed the wrong base layer that morning. Didn’t think much of it. Neither did I.
By 9 AM he’d stopped talking. Not unusual — Travis isn’t chatty on a hunt. But then I noticed his hands. He was trying to adjust his binoculars and his fingers weren’t working right. Fumbling. Dropping. He turned to look at me and his speech was thick, slurred, like he’d had four beers on an empty stomach. Said something like “I’m jus’ a little cold, gimme a minute.”
He didn’t have a minute. What he had was moderate hypothermia setting in fast, and if I hadn’t recognized it for what it was — if I’d just nodded and gone back to glassing — that hunt could’ve ended in a body bag instead of a story I tell at deer camp.
Everything here comes from that morning, from a second incident two years later when a hunting partner fell through creek ice in Montana, and from the wilderness first aid course I took after Travis’s scare. If you spend time hunting cold conditions or in backcountry winter, this will matter to you or someone you’re with. Not might. Will.
What Hypothermia Actually Is (and Isn’t)
Most people think hypothermia means “really cold.” It doesn’t. It’s a clinical condition where your core temperature drops below 95°F (35°C). Normal is 98.6°F. That 3.6-degree gap is where everything starts going sideways.
Here’s what catches people off guard — you don’t need extreme cold. Most hypothermia cases happen between 30°F and 50°F. Regular fall weather. Add rain, wind, damp clothing, fatigue, or dehydration and your body loses heat faster than it produces it. A math problem. Heat out exceeding heat in.
Most Hypothermia Happens Between 30°F and 50°F
You don’t need extreme cold to get hypothermia. Wet clothing, wind, fatigue, and dehydration at ordinary fall hunting temperatures are enough to push your core temperature below the danger threshold. A cotton base layer that gets sweaty in the morning becomes a refrigerant when the wind picks up and you stop moving. This is how perfectly avoidable situations become emergencies.
The Three Stages — Know Them Cold
Hypothermia progresses through three stages, and your treatment options narrow dramatically at each one.
Stage 1: Mild (95°F–90°F / 35°C–32°C)
The body’s still fighting. You can fix this in the field.
What you’ll see:
- Uncontrollable shivering — the body’s primary heat-generation mechanism, burns through glycogen fast
- Confusion, poor decisions — the person insists they’re “fine” when they clearly aren’t
- Fumbling hands, loss of fine motor control
- Pale, cold skin
- Slight slurring of speech
Travis was somewhere between mild and moderate when I caught it. The slurred speech and hand fumbling told me we were past early stage. His body was still shivering hard — that was actually the good sign.
Stage 2: Moderate (90°F–82°F / 32°C–28°C)
Dangerous territory. Fast.
Signs to watch for:
- Shivering STOPS. The body’s exhausted its fuel or thermoregulation has failed. The furnace just shut off.
- Severe confusion, irrational behavior — people start removing clothing (paradoxical undressing)
- Drowsiness, difficulty staying awake
- Stiff muscles, stumbling, can’t walk
- Weak pulse, blue or gray skin — especially lips and fingertips
When shivering stops, you’re dealing with a medical emergency. Period.
Stage 3: Severe (Below 82°F / 28°C)
Below 82°F, the heart becomes extremely irritable. Cardiac arrhythmias. Ventricular fibrillation. Cardiac arrest. Victim may appear dead.
Expect to see:
- No shivering, unconscious or barely responsive
- Breathing extremely slow or undetectable
- Very weak or absent pulse, rigid muscles
- Fixed, dilated pupils
There’s a saying in wilderness medicine: “They’re not dead until they’re warm and dead.” People have survived core temps below 60°F with hospital rewarming. But in the field, stage 3 means evacuation. You’re not equipped to fix this alone.
When Shivering Stops, You Have a Medical Emergency
Shivering is the body’s heat-generation mechanism. When it stops in a cold patient — not because they’ve warmed up, but because they’ve become lethargic and confused — it means the body has exhausted its fuel reserves or thermoregulation has failed. This is the transition from manageable to life-threatening. Evacuate immediately.
Field Rewarming Protocol — What Actually Works
Here’s the step-by-step that I’ve used twice and that aligns with current Wilderness Medical Society guidelines.
Step 1: Get them out of the cold. My first instinct with Travis was to get him walking — “let’s move, get the blood flowing.” That would’ve been a mistake with moderate hypothermia. Instead, I moved us 200 yards to a rock outcropping that blocked the wind. Shelter from wind matters more than shelter from cold air.
Next: Remove wet clothing. All of it. Travis’s cotton base layer was damp with sweat — acting like a refrigerator against his skin. Wet fabric conducts heat away 25 times faster than dry air. Get it off. Bare skin inside an emergency blanket is better than wet clothing.
Ground insulation is critical. The ground steals heat through conduction faster than air. Put something between the person and the earth — sleeping pad, pack, branches, anything. A closed-cell foam pad is worth its weight in gold here.
Now apply heat to the core. Not the extremities. Chemical heat packs, warm rocks wrapped in cloth — place them against the neck, armpits, and groin where major blood vessels run close to the surface.
I carry HotHands body warmers from October through March. They weigh nothing, cost almost nothing, and produce about 135°F of heat for up to 12 hours. I put four on Travis — two armpits, two against his neck — and wrapped him in my emergency bivvy.
Warm sweet fluids if they’re conscious enough to swallow. Not hot — warm. Sugar provides quick fuel for heat production. Instant cocoa is perfect. No caffeine — it constricts blood vessels and stresses an already struggling cardiovascular system.
Step 6: Monitor. Hypothermia can worsen during rewarming. Watch consciousness, breathing, and shivering. If shivering returns — good sign. The body’s fighting again.
Travis started shivering hard again about 25 minutes after we got him wrapped up and warm. Within an hour he was coherent, irritated, and insisting he was fine to keep hunting. He wasn’t. We packed out.
The Mistakes That Kill People
Let me get direct here, because these errors come from well-meaning instincts that are dead wrong.
Mistake #1: Rubbing the skin or extremities. “Rub their hands to get circulation going.” Don’t. Cold extremities may have ice crystals forming at the cellular level. Rubbing forces those crystals through cell walls — tissue damage. It also drives cold blood back toward the core, which can trigger cardiac issues. Warm the core. Leave extremities alone.
#2: Hot water on extremities first. This causes vasodilation that sends a rush of cold, acidic blood from the limbs back to the heart. Called “afterdrop” — core temperature actually decreases after you start treatment. Can trigger fatal cardiac arrhythmias. If you use warm water, it goes on the torso. Warm, not hot — 100°F to 104°F.
“Have some whiskey, it’ll warm you up.” No. Alcohol dilates skin blood vessels, which feels warm but accelerates core heat loss. It also impairs shivering. Alcohol and hypothermia together kill a staggering number of people every winter. Keep the flask in your pocket.
“Let’s jog to warm up.” With moderate or severe hypothermia, movement circulates cold peripheral blood to the core and can trigger ventricular fibrillation — the heart quivers instead of pumping. Handle hypothermic patients gently. No “let’s jog to warm up.”
Mistake #5: Assuming shivering means they’re okay. Shivering generates heat but burns energy stores at an enormous rate. A person shivering for an hour is depleting glycogen reserves and will crash hard when shivering stops — not because they’ve warmed up, but because their body ran out of fuel.
Never Rub Cold Extremities or Give Alcohol
Two instincts that feel helpful are actually dangerous: rubbing cold hands and feet (forces cellular ice crystals through tissue and drives cold blood to the heart) and giving alcohol (dilates skin vessels and accelerates core heat loss). Both can worsen a hypothermic patient’s condition or trigger cardiac events. Warm the core only — armpits, neck, groin — and skip the whiskey entirely.
Gear That Earns Its Pack Weight
I don’t carry a lot of extra weight when I’m hunting. Every ounce matters when you’re covering miles at altitude. But after Travis, I added a few things to my day pack that stay there permanently from October to April.
- Emergency bivvy sack — Not the cheap mylar blankets that tear when you look at them. A proper bivvy like the SOL Escape. Reflects body heat, blocks wind, fits a person inside. About 3.5 oz.
- Chemical heat packs — A dozen HotHands warmers weigh a few ounces total. Activate in 10-15 minutes, last up to 12 hours. Cheap insurance.
- Dry base layer in a dry bag — Merino wool top and bottom in a waterproof stuff sack. When clothing gets wet, you need dry replacements NOW.
- Instant cocoa packets and a metal cup — Warm sweet liquid is your best field rewarming tool for a conscious patient. I carry a lightweight stove for boiling water fast when fire isn’t practical.
- Closed-cell foam sit pad — Doubles as ground insulation under a patient. I use it every sit while glassing, so it’s not extra weight.
Total added weight: about 14 ounces. That pound could be the difference between a hunting story and a funeral.
If you don’t already carry a solid first aid kit on every trip into the field, fix that before you worry about anything else on this list.
When to Evacuate vs. Treat in the Field
Pretty straightforward decision framework here.
Treat in the field when:
- Mild hypothermia — still shivering, still coherent enough to answer questions
- You have shelter, dry clothing, and heat sources
- They respond to rewarming within 30 minutes
- You can keep them sheltered for 2-3 hours before moving
Evacuate immediately when:
- Shivering has stopped and they aren’t improving
- Confusion to the point of not recognizing you
- Can’t stand or walk
- Loss of consciousness at any point
- Core temperature below 90°F
- Any sign of frostbite on extremities
- Underlying medical conditions (heart disease, diabetes, elderly)
Keep the person horizontal during evacuation — moving a severely hypothermic person upright can cause blood pressure changes that stress the heart. Keep applying heat to the core during transport.
Call for help early. Three hours from the trailhead and someone’s in moderate hypothermia? Call immediately and begin treatment simultaneously. Worst case, you call off the rescue because they recovered. Nobody minds that call.
The 30-Minute Window
You’ve got about 30 minutes from recognition to knowing whether your intervention is working. That’s based on my experience and what the Wilderness Medical Society teaches.
Aggressive rewarming in those first 30 minutes almost always turns mild hypothermia around. Shelter, dry clothing, core heat, warm fluids. Thirty minutes of proper treatment and you’ll see shivering intensify, speech clear up, color return.
Hit the 30-minute mark and they’re not improving? Evacuate. The clock starts when you recognize the problem — not when you decide to act.
Travis Is Fine
He’s fine. Hunts with me every November. Still talks about that morning in unit 76, usually around a fire with a cup of coffee, usually to remind me that I said his speech was slurred when he insists he was “just talking slow because it was early.”
He carries merino wool base layers now. No cotton. Ever. He also carries his own emergency bivvy and heat packs — doesn’t rely on me to bail him out a second time.
Montana in 2021 was scarier. Full immersion in 34°F water, shivering that stopped before I got him wrapped up. That one needed SAR and a hospital — two nights in the ICU in Bozeman. Full recovery.
Two incidents in three years. Both survivable because someone recognized what was happening and didn’t waste time. The gear helped. The knowledge helped more.
Learn this before you need it. Practice at camp — wrap a buddy up, go through the steps, time yourself. Because when your hunting partner’s eyes go glassy and his words stop making sense at 8,000 feet in November, you don’t have time to look it up.
You’ve got 30 minutes.