You may not be convinced but I recall seeing a segment on a TV programme about this when I lived in London many years ago. Naturally the beverage of choice was tea rather than coffee. Infrared thermography was used to show that tea was more cooling than beer (not that any reason is needed for drinking beer).
I’ll vouch for legion’s mom. I thought it was crazy the first time I was offered hot tea in 98 deg F (37 deg C) weather, but it actually did help to cool me off. And frankly, hot tea sits better in my stomach than cold water or other beverages when I’m overheated and dehydrated.