This post is also available in: Italiano (Italian)

Those who love sea unconditionally and sailing enthusiasts in particular, know that the winter season offers unique moments for many reasons. First of all the wind, that almost never fails to blow in winter, then mooring places available at affordable prices and roadsteads always unbearably crowded in August and now almost deserted, or almost so. The only drawback is the weather, of course, especially in Northern Tyrrhenian and Northern Adriatic, where it is harsh in winter. Facing low temperatures when sailing is not a problem if you wear proper anti-exposure suits. What can be really risky under harsh weather conditions and must be taken into due consideration is the worst possible scenario, i.e. falling overboard. While in summer this event can be remembered just as a frightful situation caused by a trivial on board incident, falling in cold water is fatal or at least it reduces to few minutes your ability to survive due to hypothermia, when your body begins to lose heat rapidly till you lose consciousness.

Hypothermia starts to develop when body temperature falls under 35°C. Warning signs reveal its seriousness. Its consequences may be life-threatening, even deadly, both in high mountains and at sea. Here, all depend on latitude and consequently on water temperature. Water temperature in Northern Tyrrhenian in winter is about 5°C. After 3-4 hours in water at a temperature of 10°C a person does not have many chances to survive. In the Arctic Sea, for example, survival chances are reduced to a few minutes. Immersion in water causes a greater heat loss compared to air exposure. This is due to the difference of temperature between the body and the surrounding environment, i.e. the sea. Heat can be lost from the body very quickly when it is placed in cold water as water causes 26 times higher heat loss from the body than air does under the same temperature. 

Hypothermia early symptoms are cold shock causing deep gasp and severe hyperventilation with sense of disorientation and dizziness. After a while, as the situation gets worse, a heart attack occurs and the next step is death. Scientific surveys have shown that in the Mediterranean Sea in summer hypothermia occurs after between 2 and 12 hours after falling in water. Luckily, it is often a mild hypothermia occurring when body temperature is between 35 and 32°C. Generally speaking, survival time is lower than 15 hours when water temperature ranges between 15 to 20°C and sinks to 6 hours after falling in case water temperature is between 10 to 15°C. If water temperature is between 4 and 10°C, death comes not later than 3 hours and only 1.5 hours after falling in case water temperature ranges between 2 to 4°C. Survival time is only 45 minutes if a person falls overboard at 2°C water temperature. Below this temperature, death occurs in a very few minutes.

Hypothermia is moderate when body temperature lowers to 28-32°C. Hypothermia is severe when body temperature is below 28°C. An increased heart rate is among the first symptoms. This is due to haemoglobin not being able to deliver oxygen to the tissues anymore. As hypothermia becomes more serious and the body loses most of its heat, bradycardia occurs and airways become blocked. Tissue necrosis due to the lack of oxygen is a typical consequence. This is the reason why alpinists may risk limb necrotizing (their fingers, at best) due to extreme cold exposure. When body temperature goes below 28°C, the person goes into coma, pulmonary oedema and no response to light of the eye pupils occur and the person inevitably dies.

In a very few cases, alpinists suffering from severe hypothermia (body temperature at 25°C) have been rescued. In these cases highly specialised prompt medical attention has made a difference. At sea, unfortunately, rescue time is often longer as it is difficult to locate people overboard. It is quite easier to search an injured mountain climber at 4,000-m height than a missing person at sea. Here, localization speed and quality of medical treatment make the difference between life and death.

Immediately after the recovery of someone who has fallen overboard, follow these tips to prevent any further heat loss that might be fatal. Move the victim as gently as possible, position him face up, keep him sheltered from wind, remove wet clothing and use isothermal blankets. If you fall overboard in cold water, do not make the mistake of trying to swim hoping to get warm, as what happens is precisely the opposite: heat loss is faster. Experts recommend to assume, as far as possible, the so-called Help Position, i.e. the Heat Escape Lessening Posture. This is a semi-standing position, the head kept afloat by the lifejacket, knees drawn to the chest and arms to the sides.

Wearing a survival suit is of course of vital importance if you fall overboard. Special high-tech clothing such as anti-exposure coveralls or drysuit may lengthen survival time. As neither kind of survival clothing is cheap, it is usually prerogative of professional sailors, hardly seen in the peak of a pleasure boat. So, what really makes a difference is how fast the recovery will be. This is why a personal emergency device like e.g. a Personal Locator Beacon (PLB) should always be worn, so that a person in distress can be quickly located and rescued.