
Editor’s Note: This case study is based on a real-life incident from the early 1980’s.
The Setting
You and three friends are on an early winter ski trip. To shorten the route, the group decides to cut across a lake, despite previously agreeing to avoid the lakes due to thin ice.
About 20 yards from shore you warn the others of “funny ice,” and suggest the group turn around. As you stop to talk it over with your companions, you break through the ice and sink up to your chest. Fortunately, the sled you’re towing keeps you from falling through completely.
Remembering the scene size-up priority of rescuer safety (and scared they would also break through), your companions retreat to safety. They coach you to relax, which you find amusing considering you’re the person in the water. You unbuckle your pack and detach from your sled, but then slip into the water up to your chin. You struggle for a few minutes, gasping and hyperventilating, before realizing you are standing on the lake bottom. After calming your breathing, you release the ski bindings and, with the help of your companions, you crawl out of the water, onto the ice, and away from danger.
The light is fading as the sun sets. It is 15°F (-9.4°C). Your clothing and hair quickly freeze. You are shivering.
SOAP Report
Subjective
The patient is a 26-year-old male who fell into a lake while skiing, and was able to self-extricate after 5-10 minutes. He is presently complaining of being very cold, shivering violently, and is unable to help himself.
Objective
Patient Exam
The patient was not submerged and has no apparent injuries.
Vital Signs
Time |
4:30pm |
Level of Responsiveness (LOR) |
A+OX4 |
Heart Rate (HR) |
110, strong, regular |
Respiratory Rate (RR) |
28, shallow, regular |
Skin Color, Temperature, Moisture (SCTM) |
Mucous membranes pink, cool, dry |
Blood Pressure (BP) |
strong radial pulse |
Pupils |
not noted |
Temperature (T°) |
not taken |
History
Symptoms: |
None |
Allergies: |
Unknown |
Medications: |
Occasional non-prescription pain medication, none taken today |
Pertinent Hx: |
None relevant |
Last in/out: |
Breakfast & lunch today, 2 liters of water during the day |
Events: |
None relevant |
STOP READING!
What is your assessment and plan? Take a few minutes to figure out your own assessment and make a plan. Don’t cheat—no reading on without answering this first!

Assessment
Patient is mildly hypothermic but at risk of becoming seriously hypothermic and/or frostbitten.
Plan
- Remove wet clothing. Replace with dry.
- Use a hypothermia wrap to warm patient.
- Set up camp. Start a stove and build a fire.
- Feed and hydrate the patient.
- Dry the patient’s wet clothing.
Anticipated problems
- Hypothermia progressing to moderate or severe hypothermia.
Notes from NOLS on Cold Water Submersion
Many people believe that if you fall into cold water you become immediately hypothermic. That is not the case, says Dr. Gordon Giesbrecht, who combines scientific research with extensive Arctic expedition experience to educate the public about hypothermia and cold weather survival. Dr. Giesbrecht’s message is simple: “1 minute, 10 minutes, 1 hour.”
Surviving the first minute is key when you're immersed in cold water. It’s normal to immediately gasp and breathe rapidly. Cold water is shocking. It hurts. If your head goes underwater at this point and you inhale water, you may drown. To keep your head above the water, grab the edge of your boat or the ice. After a minute or two your gasping should subside and, as your skin numbs, the intensely uncomfortable cold sensation should wane.
There is roughly another 10 minutes before muscles become too cold to move effectively. Use this time to get out of the water, or to secure yourself against drowning.
Next, you will have about 1 hour before you become severely hypothermic.
A first responder can use this knowledge to make a thoughtful, careful, and prompt response. We want to rescue and treat this patient quickly, yet we know we don’t need to panic and make rushed decisions that will cause rescuers to become more patients.
The Tale Continues...
You stand helpless while your wet clothing is quickly removed and replaced with dry clothing, hat, gloves, scarf and socks. Your fingers and toes are cold but not frozen. Your friends create a hypothermia wrap around you: you are placed in a sleeping bag, on a foam pad, with two other sleeping bags under and on top. The hypo wrap is completed with the tent fly wrapped around everything else. You shiver uncontrollably.
Warm drinks, food, and hot water bottles for your cold fingers and toes are prepared on the stove. A roaring campfire is built, giving you a sense of comfort and helping to dry your gear. Your shivers subside and in less than an hour, you finally feel warm.Eventually, the tent is set up for the night and you are moved inside, still snug in your sleeping bag.
End of the Tale
You’re exhausted from the cold, soaking, and shivering, but the next morning after breakfast you are able to continue the trip.
Notes from NOLS on Hypothermia Treatment
The hypothermia wrap, as described above, is a sound field technique. If you can’t strip the wet garments, use a tarp between the wet patient and the insulation to keep the insulation dry. Many patients, unless they are exhausted or severely hypothermic, will warm in the hypothermia wrap using the heat generated from their metabolism and from shivering.
Warm sweet drinks provide the necessary calories to fuel the energy-intensive shivering. The key word here is sweet. Warm drinks are comforting—and that is important—but don’t add a lot of heat. Humans are 70% water (15 gallons in a 170 lb. person). Adding 8 ounces of warm water to 15 gallons of cold water will not appreciably change the temperature. The value of the sweet warm drink is in the calories that fuel our metabolic fires, and fluid for hydration.
This group didn’t place a second person in the sleeping bag with the cold patient. We don’t think much body-to-body heat is gained in this way. In this incident, the rescuers decided they were more valuable making camp, building a fire, filling hot water bottles, and cooking dinner.
If you're helping a patient that does not warm, or was in the water long enough to become severely hypothermic, field warming becomes challenging, if not impossible. They will need to be evacuated to a hospital. The hypothermia wrap is still a sound foundational treatment. Protect the cold patient from becoming colder by using hot water bottles on the chest, armpits and groin. Avoid having the patient stand or walk; rough treatment can trigger cardiovascular collapse.
A patient who succumbs to hypothermia after becoming exhausted, hungry, and dehydrated will have a harder time warming themselves. Luckily, this patient had eaten two meals earlier in the day and was hydrated. With adequate calories they were able to warm themselves through shivering in the cocoon of the hypo wrap.
Written By
Tod Schimelpfenig
As a NOLS Instructor since 1973 and a WEMT, volunteer EMT on ambulance and search and rescue squads since the 70s, Tod Schimelpfenig has extensive experience with wilderness risk management. He has used this valuable experience to conduct safety reviews as well as serve as the NOLS Risk Management Director for eight years, the NOLS Rocky Mountain Director for six years, and three years on the board of directors of the Wilderness Medical Society, where he received the WMS Warren Bowman Award for lifetime contribution to the field of wilderness medicine. Tod is the founder of the Wilderness Risk Manager’s Committee, has spoken at numerous conferences on pre-hospital and wilderness medicine, including the Australian National Conference on Risk Management in Outdoor Recreation, and has taught wilderness medicine around the world. He has written numerous articles on educational program, risk management and wilderness medicine topics, and currently reviews articles for the Journal of Wilderness and Environmental Medicine. Additionally, he is the author of NOLS Wilderness Medicine and co-author of Risk Management for Outdoor Leaders, as well as multiple articles regarding wilderness medicine. Tod is currently the Curriculum Director of NOLS Wilderness Medicine.