iirc warm water ease the work of kidney, such as when received liquid both kidneys in the process would turn the temperature higher than room-temperature (probably related to our body temperature too which is around 35~36°C) in addition imo warm water makes you craving for more water compare to room tmp/cold water
Edit: can't really relate to the warm water bit. Wonder if it's because my mom always boiled water and stick a pitcher of it in the ref so our drinking water is always cold.
Warm water can help settle your stomach, although it was usually my father who talked about its benefits. If you don't like the flavor, making some tea's not a bad idea. Green tea has many health benefits, along with chamomille.
Warm water in the morning helps to kickstart my stomach, always feel super hungry in the morning after a cup of warm water. Warm water to me is a room temp water with one-fourth of hot water.