I like very cold water with lots of ice on hot summer days, but I’ve heard others say that water at room temperature is healthier. The debate over water temperature has been going on for a least a hundred years. Here’s what it says in a 1922 magazine:

A word about drinking water is not amiss just here. Iced water may seem very desirable when one is thirsty, but water without ice is far better for drinking purposes, as it does not so suddenly reduce the temperature of the stomach.

American Cookery (August/September, 1922)