I found a study titled “Skin temperatures during sunbathing and some observations on the effect of hot and cold drinks on these temperatures [proceedings"] from 1977.
http://jp.physoc.org/content/267/supplement/1P.full.pdf
This study did seem to indicate a decrease in skin temperature after the hot drink but not the cold.
However, there is a significant problem with this study: they used ONE subject.
This study cannot possibly stand with such a low sample size. Without further peer reviewed studies, I expect most of the evidence is anecdotal and I would go with hydrating yourself in a way that feels most comfortable and refreshing assuming you are not suffering heatstroke or hypothermia, in which cases there are prescribed first aid treatments that should be followed.

And yay for you, David, for liking peach iced tea, too! It’s my favorite!

Yes, drinking something hot will make you sweat, especially if you’re overheated already, but sweating is not 100% efficient and the fundamental physics means that it cannot offset the rise in stomach temperature caused by pouring in what you describe as a “steaming hot tea”.

If it didn’t, why then do they give soccer players in South American, African and Middle Eastern countries steaming hot tea at half time? It’s not because of the culture (well maybe partly), but because it cools you down. Do you really think the biggest sport on earth, with more money, science and etc invested into it than most other things in life, would be doing this if it didn’t help? I will take it from professional sports scientists and doctors, thank you very much (speaking to you, David Bradley), rather than trust some pseudo-physician online.

We do mention the idea that the hot tea causes the body’s temperature controls to kick in and because these are not perfect, they could overshoot the mark. But, I just ran up the stairs to my office and am not drinking a hot cup of tea, which has left me feeling slightly flushed, and certainly warmer inside than before.

Seeing as you’re such a stickler for the science, why not provide us with a reference or two for this legendary experiment? If it was carried out on a statistically significant cohort and shows actual temperatures of the subjects before and after hot and cold drinks…then we might be closer to being convinced.

The assertion that they tested was the one that stated that drinking a hot tea after exercising would cool you off faster than drinking a cold drink. So what they did was have a test subject exercise for some minutes and then drink a hot or cold drink and then record the results with a relatively new invention, the thermal imaging camera.

The thermal images clearly showed that the person who drank a hot tea after being hot from exercise was lowering his body temperatures faster than someone that drank a cold liquid after exercising. The principle that causes this is know as “Like cures like.” Where a specific condition is changed by administration of a similar condition. The heat of the tea informs the body that it is hot and the body response is to cool itself off.

Sweating has done it’s job, as have other physiological functions to expose the body’s heat to the environment where it will radiate away more efficiently and continue to do so – because it’s not a closed system.

The same conclusions are to be drawn from experiments in extreme cold. Those with wet skin (either from sweat or falling into icy water for example) will lose body heat, far faster than the same person with dry skin.