Exact Answer :- Around 12 hours
Well, it is quite difficult to define this term “cold water”. Sometimes, it is said to be the temperature around 70°C. According to the National Oceanographic Data Center, 21°C- 25°C is where most people feel comfortable swimming. Well, it’s still considered to be cold.
The normal body temperature of a human being is 32°C. But whatif a human body is immersed in cold water(having nearly double it’s temperature)? The body first leads to disorientation further leading to unconsciousness and death.
How Long A Person Survives In Cold Water?
| Water Temperature ( in °C) | Expected Survival Time |
| 0.3 | Under 15 to 45min. |
| 0.3 – 4.5 | 30 to 90 min. |
| 4.5 – 10 | 1 to 3hrs |
| 10 – 15.5 | 1 to 6 hrs. |
| 15.5 – 21 | 2 to 40hrs. |
| 21 – 26.5 | 3hrs. to indefinite |
| Over 26.5 | indefinite |
The expected survival time depends on the temperature of water, the age and physique of the victim and the facial immersion.
While talking of age, the younger the victim, the more chances of survival. It has been reported that children have been rescued after 30minutes of drowning in cold water.
The small victims have large surface area to volume ratio thereby resulting in greater heat loss.
The obese persons have a lot of adipose tissue which helps is production of heat and insulation. This is why, obese persons can survive better than lean persons although they may suffer more breathing problems as compared to lean persons.
Another factor which affects the expected time of survival is the facial immersion, which means how much portion of the body is immersed underwater.
Water takes away more heat than air, even if the temperature is higher than air temperature. The more the body is immersed, the faster the heat is drained away.
While talking of temperature, the survival is different at different temperatures. When the temperature of water is over 26.5°C, the person can survive indefinitely but upto 12 hours. When the temperature is between 21°C to 26.5°C, the person can survive upto 3hours.
When the temperature lies in the range of 21°C to 15.5°C, the person can survive upto 2hours. When the temperature falls below 15.5°C but ranges within 10°C, the person can survive maximum upto one hour.
When the temperature falls below 10°C, the person survives for less than one hour. The expected survival time when the temperature falls down gradually.
Why Can A Person Survive That Long In Cold Water?
The body first reacts by the cold shock response during the first three minutes. During this period, the person starts breathing heavily and uncontrollably. He/she is panicked and shocked which can strain the person’s body leading to cardiac arrest. The person thrashes helplessly in water for some time and then the body gets adjusted and tries to find survival techniques.
Longer stays in cold water can even result in frostbite( freezing of muscle, skin and nerve tissue) and hypothermia (drop in temperature of the body). At first, hypothermia occurs which leads to frostbite.
Cold water takes away the body heat 32 times faster than cold air. First of all, cold water takes away heat from the body. To replenish this heat being drawn by cold water, the body adopts different methods like shivering to produce body heat. The person also starts swimming as a survival technique.
However, shivering extracts heat from the body at a faster pace. Swimming and other such activities deprive the body from heat further more. The muscles get fatigued leading to the freezing of the body.
As the body temperature falls below 32°C, the body stops receiving the sensation of cold or pain. This is because the muscles get stiffened cold paralyzes the nerves. The performance of brain is reduced thereby reducing the movement of the body. The body gets numbed and stops responding. At this point of time, the person fails to grasp the lifesaving resources.
The decrease in performance of brain or injuries in brain may also lead to Amnesia (also called as short- term memory). This memory loss may be temporary or permanent.
Once the temperature falls below 29°C, the heartbeat reduces to almost 2 to 3 times per minute. But when the temperature falls below 20°C, blood vessels dilate thereby reducing the blood pressure and leading to death.
The person’s recovered successfully may also show some symptoms like death which includes blue coloration of the body, stoppage of breathing, dilation of pupils etc. This does not exactly represent that the person is dead. The person can still be resuscitated.
Conclusion
The body strives a lot to survive in cold water. But, at a certain point it fails and the person dies. At first, one should try to get out of water as soon as possible. The person should not panic and keep trying his/ her best to survive.