The standard for swimming pool water temperature is between 22℃-26℃. Generally, the temperature of swimming pool is between 26℃-28℃. Everyone knows that the body temperature of the human body is 37℃. The temperature difference is close to 10℃. Feel cold. Why does the temperature of the pool water have to be so "low"?
Cold water is an effective radiator
With the same amount of exercise, swimming consumes more energy than land sports, which is why everyone loves swimming. But everyone does not know that this also determines the water temperature of the swimming pool. Everyone has this experience: whether it's swimming or paddling, it feels cold just after entering the water, but after playing it may even be hot enough to sweat. This is because exercise consumes energy and also generates heat, and during exercise, metabolism speeds up and body temperature rises, which requires cold water to cool you down and make you feel comfortable. If the water temperature is not lower than body temperature, then water, a beneficial heat dissipator, will not be able to function.
Moreover, if you pursue comfort when entering the water, the water temperature must reach or exceed the body temperature. At this temperature, everyone does a little exercise instead of swimming but sauna, because warm water can’t quickly reduce the effects of exercise. The excessive heat is taken away.
Hot and cold relaxation, vasoconstriction
When you first enter the water, water below body temperature will constrict the blood vessels of the skin to reduce heat dissipation. After exercising, the heat generated by the exercise will be released and the blood vessels of the skin will expand. This shrinks one, so that the cardiovascular system that is not usually exercised can also exercise. This is a good exercise to prevent cardiovascular diseases. .
In addition, when it is cold, blood vessels in the skin constrict and blood flows back to vital organs such as the brain to protect them from harm. When it is hot, the blood vessels of the skin expand and the blood stays more on the surface of the body. The blood flow of those vital organs will naturally decrease. The brain’s nutrition and oxygen are insufficient, how can it react quickly? Naturally, it feels chaotic.
Give muscles a sense of strength
Even a tiny movement of the human body is completed by muscle contraction. The muscles that declare strength must be contracted before they can be seen. Cold water not only helps the blood vessels contract, but also helps the muscles contract well, so that people who exercise in the water feel full of power to complete the action. But if it is in warm water, it can be counterproductive. Warm water, slapping your body like a massage, all the muscles will relax. Feeling comfortable is comfortable, but if you want to move, you will get twice the result with half the effort, and people will feel very tired. (Everyone knows that after taking a hot shower, you will feel tired. Of course it is a kind of comfortable tiredness.)
Fatal swimming pool heatstroke
Swimming in warm water is more tiring and requires more energy. And the heat brought by consuming more energy cannot be taken away by warm water, which causes the body temperature to rise all the way. In order to dissipate heat, the blood vessels of the skin expand more, resulting in insufficient blood supply to vital organs in the body. At the same time, in order to lower the temperature, the human body will sweat a lot, and it is expected that the evaporation of sweat will take away more heat and achieve the purpose of cooling down. However, swimming in warm water not only fails to complete this task, but also causes dehydration of the body.
Body temperature cannot be adjusted, dehydration, heat stroke is likely to occur (not only in summer, "fainting" often occurs in a hot bath is also heat stroke), this is a very fatal emergency, prone to abnormal heart function , Unconsciousness and difficulty breathing. It is critical that these situations occur on land, and it is even more dangerous in the water.