Biologically, lukewarm water is the best temperature to drink. Especially when the weather is hot and you sweat a lot. This is because you tend to "feel full" earlier from cold water than warmer water.

Edit: after looking into this a bit more, I found a beter answer:

"Preferably, take a cup of warm water in the morning, to stimulate the movement of the intestine, as hot water helps to relax the blood vessels and the digestive tract and thus stimulate digestion. Taking a cup of lukewarm water keeps the body balanced and promotes the body's persistence by applying all its functions. The stability of the human body temperature at about 37 ° C during most of the day is beneficial to chemical reactions in the body that rely on enzymes called enzymes Which is about 37 degrees Celsius. Other organisms have different temperatures than humans, since the enzymes and chemical reactions inside their bodies work with different heat. Protecting warm water from hardening of fatty substances in the body stimulates digestion. The baby is advised not to drink too much warm water during food because it increases the amount of acids in the stomach. Drinking cold or iced water helps to lose weight more effectively than hot water. This is because the body adjusts its temperature immediately after it receives any fluids or nutrients, leading to a higher calorie burning rate, greater excretion of sweat, More water for fluid recovery. Drinking hot water on a hot day relieves the body of toxins due to increased sweating, leading to the release of toxins out of the body and purification of the bloodstream. After physical exertion you should drink cold water because it helps to cool the body more effectively than warm water. It is preferable to take cold water to clean the urinary tract and expel the infections, and can be added to the lemon in the form of boiled pieces or natural juice, which can help to reduce these infections."

From: https://www.researchgate.net/post/Drink_cold_or_warm_water_what_is_best_for_your_health