It Could Happen to You!

How an Experienced Diver Developed Hypothermia

Story by John Keytack

It was a fairly warm spring day for Central New York. Outside temperature was 66 and cloudy. There was a steady, cold rain and a light wind, making the wind chill 45.


I was suited up to get my open water certification for dry suit that day. I had been diving for more than a year, and had dived in my dry suit before. I was using a Bear’s Dry Dive with a hood, 5 mil. gloves, and 80 pound steel tanks. Although I’m Nitrox certified, I was on regular air.

I was diving with people I knew, which made me feel comfortable. The dive master that day, Frank, had been my dry suit instructor. Dan was going to be my dive buddy, and we had dived together before.

The day started off normally. We had a rented cottage we were using on the shores of Skaneateles Lake, which is one of New York’s famed “finger lakes.” I arrived early that morning and unloaded my gear, taking it up to the cottage. Everyone gathered and shared dive stories over coffee and hot chocolate while we set up.

I was diving with 22 pounds of weight, including my ankle weights. We buddy checked each other’s equipment before going in the water. As I said, I had dived with Dan before and we knew each other’s capabilities.

 The surface temperature of the water was just 45. We weren’t going that deep, so “no problem,” I thought. Instead of wearing the White’s thermals, I had a sweat suit on underneath my dry suit. That was my first mistake.

We had a dive briefing and planned our dive before setting out. It was supposed to be a shallow water dive, lasting just 45 minutes. We made judicious entries in our log books, and after buddy-checking each other’s gear we headed for the open water.

We entered the water about 9 a.m. for our first dive, with 2,900 in my tank. The surface was calm with small surf, and a slow current. I couldn’t get perfect buoyancy, so I had to add more weight, making a total of 28 pounds. I immediately began to notice the cold, but tried to shrug it off. After all, I had dived in waters almost this cold in wet suits.

Visibility in the water varied, from 10 to 20 feet. At 15 feet depth we hit the first thermocline and the water temperature was only 41. The four degrees difference made a big difference. The cold began bothering me. I first noticed it on my face around my mask and in my hands. After a while my hands began hurting and it became difficult to move my fingers.

As part of our dive, Frank had planned several skills and buddy cares. We did a mask clear, regulator clear two way, and regulator retrieval two ways at 40 feet. When we did buddy sharing the second time my air two failed. Later, we decided it was because I pressurized my system before I connected my air two, since the coupling couldn’t make a good seal. That was my second mistake. I had to make an emergency ascent, but continued our dive.

 The cold was beginning to bother me more and more. I could feel it up my back, all the way to my head. It was a punishing cold. My feet began to feel cold, as well. I didn’t realize it at the time, but they would soon become numb. By the time we got out of the water on the first dive I felt chilled to the bone.

In the winter time, the first vehicles you see slid off the roadways are 4WD and SUVs. That’s because they give their drivers a false sense of confidence. Like the country/western song says, “ten foot tall and bullet proof.” That’s how I felt in my dry suit. I thought I was immune to the effects of cold, just because I was wearing a dry suit.

 Everybody wants to log another dive, and I’m no different. After keeping a 10 minute surface interval I went back into the water. That was my third mistake. Within minutes I had begun to shake uncontrollably. Frank saw me shaking and ordered me out of the water. I went to the surface and pulled off my mask. My breathing was rapid and shallow.

We had a safety swimmer on the surface. He could tell I was in trouble. He came over to me and literally had to pull me from the water.          I was shaking badly. Another dive assistant on the shore helped me get out of the water. Together, they held me up while we walked back to the cottage.

By now, I was confused in addition to shaking. I couldn’t feel my feet or hands. Two other divers had to peel my gear off. They wrapped me in blankets and set me in front of an infra-red heater. I couldn’t use my hands. They plied me with hot chocolate for the next two hours, checking on me every few minutes.

It took me two hours to recover to a point where I could drive home. I could use my hands again, but both feet were completely numb. Everyone said that if I had stayed in the water another 10 minutes I would have had to be taken out by an ambulance.  My hands and fingernails were totally white.

My normal body temperature is 96.8, instead of 98.6. By the time I got home my temperature was only 95. I had lost that much of my core body temperature.

Signs of Hypothermia (from Wikipedia)


Symptoms of mild hypothermia may be vague with sympathetic nervous system excitation (shivering, hypertension, tachycardia, tachypnea, and vasoconstriction). These are all physiological responses to preserve heat. Cold diuresis, mental confusion, as well as hepatic dysfunction may also be present. Hyperglycemia may be present, as glucose consumption by cells and insulin secretion both decrease, and tissue sensitivity to insulin may be blunted. Sympathetic activation also releases glucose from the liver. In many cases, however, especially in alcoholic patients, hypoglycemia appears to be a more common presentation. Hypoglycemia is also found in many hypothermic patients because hypothermia often is a result of hypoglycemia.


Low body temperature results in shivering becoming more violent. Muscle mis-coordination becomes apparent. Movements are slow and labored, accompanied by a stumbling pace and mild confusion, although the victim may appear alert. Surface blood vessels contract further as the body focuses its remaining resources on keeping the vital organs warm. The victim becomes pale. Lips, ears, fingers and toes may become blue.


As the temperature decreases further physiological systems falter and heart rate, respiratory rate, and blood pressure all decreases. This results in an expected HR in the 30s with a temperature of 28 °C (82 °F).

Difficulty in speaking, sluggish thinking, and amnesia start to appear; inability to use hands and stumbling is also usually present. Cellular metabolic processes shut down. Below 30 °C (86 °F), the exposed skin becomes blue and puffy, muscle coordination becomes very poor, walking becomes almost impossible, and the person exhibits incoherent/irrational behavior including terminal burrowing or even a stupor. Pulse and respiration rates decrease significantly, but fast heart rates (ventricular tachycardia, atrial fibrillation) can occur. Major organs fail. Clinical death occurs. Because of decreased cellular activity in stage 3 hypothermia, the body will actually take longer to undergo brain death.

Treatment (from Wikipedia) 


Rewarming technique


Passive rewarming


Active external rewarming


Active internal rewarming

Aggressiveness of treatment is matched to the degree of hypothermia. Treatment ranges from noninvasive, passive external warming, to active external rewarming, to active core rewarming. In severe cases resuscitation begins with simultaneous removal from the cold environment and concurrent management of the airway, breathing, and circulation. Rapid rewarming is then commenced. A minimum of patient movement is recommended as aggressive handling may increase risks of a dysrhythmia.

Hypoglycemia is a frequent complication of hypothermia, and therefore needs to be tested for and treated. Intravenous thiamine and glucose is often recommended as many causes of hypothermia are complicated by Wernicke’s encephalopathy.


Rewarming can be achieved using a number of different methods including passive external rewarming, active external rewarming, and active internal rewarming. Passive external rewarming involves the use of a person’s own heat generating ability through the provision of properly insulated dry clothing and moving to a warm environment. It is recommended for those with mild hypothermia. Active external rewarming involves applying warming devices externally such as warmed forced air (a Bair Hugger is a commonly used device).  In austere environments hypothermia can sometimes be treated by placing a hot water bottle in both armpits and groin. It is recommended for moderate hypothermia. Active core rewarming involves the use of intravenous warmed fluids, irrigation of body cavities with warmed fluids (the thorax, peritoneal, stomach, or bladder), use of warm humidified inhaled air, or use of extracorporeal rewarming such as via a heart lung machine. Extracorporeal rewarming is the fastest method for those with severe hypothermia.

I was “messed up” that evening. I couldn’t think straight and my actions were awkward…even for me! Lol! It was two hours before I had full feeling in both my hands and was able to use them again. It was three-plus hours before I regained full feeling in both my feet. I ate light, and had hot beverages and soup. The next morning I was fine again. I went back out and finished diving with my “buddies.” That time I made sure to wear my White’s thermals, along with my sweat shirt and pants! I had a glorious dive, and was none the worse for wear. We did a “tour dive” and I was fine.

The lesson learned was that I came really close to “buying the farm” through my own mistakes. Like many divers, when I suit up I think I’m John Wayne, but I’m not. Also, wearing a dry suit gave me a false sense of confidence. A dry suit offers some protection, but it doesn’t make up for common sense.  Divers should always wear the appropriate gear for the environment they are diving in. More importantly, divers should know when they’ve reached their limits. No one wants to appear to be weak, or “wimp out” in front of others, but there’s a strict line between being proud and being stupid. I learned where that line is the hard way.