Most water health risks are associated with the open water swimming. And the most lethal of them is swimming in the cold water, which is totally different from swimming in warm water. Research show -- and water accidents statistics bear this out -- that sudden immersion in very cold water (below 15 degrees C) is very dangerous and may lead to thermal shock and hypothermia, and it should be avoided as much as possible. The severity of the effects of cold shock is directly proportional to the water temperature peaking between 10 to 15 degrees C.
Cold water cools down the body 25 times faster than cold air does. Any physical activity like swimming or struggling for survival in the water only increases the body's heat loss. Survival time is reduced to minutes. Strong swimmers die before swimming 100 meters in cold water. If water temperature is less than 5 degrees C, victims die before swimming as much as 30 meters.
Muscle rigidity and dangerous loss of manual dexterity, physical weakness occurs at body temperature about 35 degrees C. Mental ability also deteriorates at this point. Unconsciousness occurs when the body's core temperature falls below 30 degrees C. If drowning doesn't happen first, a person dies at the body's core temperature of about 27 degrees C.
There are four types of cold water health risks in which a swimmer may die:
1. Cold shock (3 to 5 minutes) - fast immersion in cold water can cause death.
2. Swimming failure (up to 30 minutes) - inability to swim.
3. Hypothermia (above 30 minutes) - decreased body temperature.
4. Post rescue collapse (on or soon after rescue).
For those people subject to potential heart conduction defect (elderly and middle-aged tourists), immersion in cold water dangerously increases the chance of fatal cardiac arrhythmia (irregular heart beat).
Other water health risks are stipulated by biological reasons.
Illnesses caused by poor water quality include stomach cramps, diarrhea, vomiting and sore throat. The elderly, children and people with weakened immune systems have a greater risk of getting ill when swimming in waters that harbor natural or man-made contaminants. Microscopic germs are found in all natural waterways, and these germs can pose serious health risks.
Microorganisms can enter the body through natural apertures like mouth, nose and ears, as well as through open cuts and wounds. Therefore, swallowing the water and immersing one's head increase biological water health risks. Waterways used for recreational purposes can never be risk-free, but there are several ways as how to reduce water bacteria risk. These precautions include:
Do not swim near water dumping and dirty areas.
Do not swim in areas marked with warnings against swimming.
Avoid swimming during and after heavy rains.
Avoid swallowing the water. Keep your head above water when swimming.
Avoid swimming with open cuts or wounds.
Shower right after swimming.
Common sense is the best practice in avoiding water health risks. Athletes must not share water bottles, towels, or swim suits; and all of these items must be washed regularly. And don't forget to wash yourself while you're at it. After exiting from a lake, pool or ocean it's always a god idea to take a shower and scrub yourself down. That way any germs on your body go right down the drain!