If it is hot, you are already inclined to a glass of cold water, preferably with ice cubes and a lemon slice.Tasty, but it also has the best cooling effect? Very often it is said it is better to have a cup of hot tea. What works better, a warm or cold water drink in hot weather? Drinking hot tea would be better than drinking cold drinks, because the high temperature creates a temporary increase in your body temperature. Your body adapts to this by letting your body temperature drop. That way your body cools. The same would apply vice verse, if you drink cold water, your body temperature rises.
A beautiful story and true. However, there is one very big but in this story, you would have to include drinking lots of hot or cold water if it will have an effect on your body. A single glass namely helps nothing.
The temperature of what you drink, is not so important. Much more important is that you drink plenty of fluids, even if you are not thirsty yet. On warms days, you sweat more, so you need to drink more than usual. When you urinate less than usual or if your urine is dark in color, you drink too little. An adult usually drink about two liters of water per day from beverages. At high temperatures, it is good to drink at least two liters each day. Tea and water as well as coffee is good to drink as well as a fluid intake. Many people think that coffee is a diuretic, but that is a fable. Alcohol on the other hand is a diuretic. It is always handy to carry a bottle of water when you go on the road. So you always have water available if you are thirsty.
It is not necessary to eat extra salt when it is hot. If you just eat, you get enough salt. The chances that you will get a shortage of salt by sweating is very small.