If you are tired and thirsty, which water would you choose, cold or warm? Which one is better in your opinion? You might think that it is just a matter of preference but it is not so. Cold Water is likely to refresh you. So, why is cold water refreshing?

Refreshing Cold Water

Why is Cold Water Refreshing?

Hydration is necessary to regulate your body temperature, deliver nutrients to the cell and ensure the proper functioning of various organs. The major means of getting hydrated is by drinking water. Due to its distributive action, water refreshes us. In this context, both cold and warm water are equivalent.

Refreshing also means activating our brain or nerve cells. Coldwater is usually treated refreshing as majority of people. This relatively good refreshing nature of cold water can be understood if we can distinguish well about hot and cold water. Also, the way our nerve cells perceive cold and hot water must be understood.

Difference Between Cold Water and Warm Water

The major difference between cold and warm water is their temperature. Coldwater can drain heat energy from the cells while warm water can provide heat energy to the cells. This difference can play a major role in proving the refreshing action of cold water.

Also, water with high temperatures can always dissolve more impurities than cold one. This means cold water is likely to have fewer impurities than hot water. On the basis of surface tension, cold water has high surface tension than warm or hot water. So, warm water can spread more when spilled than cold water on the same surface. This gives warm water more surface of contact than cold one when spilled. This favors warm water instead.

Since we have different receptors to perceive hotness and coldness, the temperature of cold and warm water are perceived by different sets of nerves. This difference has created a distinction in the way of their perception.

Perceiving Cold and Warm Water

Our body is embedded with different kinds of thermoreceptor cells to perceive coldness and hotness. Cold receptors and hot receptors are different morphologically, cold receptors are thinly myelinated while warm receptors are unmyelinated. This makes cold receptors to conduct faster than warm receptors.

The speed of conduction can be a possible cause for the difference in the sensation of cold from hot. The firing rate of the nerves can be better for cold water proving it better stimulating than its warm counterpart. Cold receptors have a high spatial density in the tongue too. This makes the sensation of cold water better than hot water.

Another point of view for this problem is heat energy transfer. Coldwater drains heat and warm water gives heat energy. This implies that as we drink cold water, the energy drains so that the cellular metabolisms must accelerate to regulate the temperature and suffice to drain of energy. On the contrary, warm water is likely to give energy and slow down cellular metabolism for maintaining the temperature.

There has not been more scientific study in this particular topic due to the difference in views of people of preference for cold and warm water. Also, People often argue that it depends upon the feeling of cold and warmth saying cold water is refreshing while you are feeling hot and vice-versa. But, still, we can say that cold water is a better stimulant than hot one whatever the preferences of people. Activation of cells and speedy transfer of stimulus due to cold water makes it more refreshing or stimulating than hot water.

Meanwhile, the coldness and hotness below the threshold 0 degree Celsius and above 50 degrees Celsius can be pain-inducing because it can destroy the nerve cells. So, beyond those limits, we cannot make a comparison of the temperature of the water. However, within this range, cold water proves better to warm water.

Ashwin Khadka is a PhD Scholar in Nano Energy and Thermofluid Lab in Korea University, Republic of Korea under Korean Government Scholarship Program. He has a Masters Degree in Physics from Tribhuvan University, Kathmandu, Nepal. He is a science enthusiast, researcher and writer.