If your social circle is anything like the writer of this blog post’s, then you’ve got at least one or two know-it-all buddies who just can’t help themselves: they need to share facts. They need to share them with you. And they need to share them with you constantly.

Now, facts in these instances might be better stylized as “facts,” facts, or facts*. Not to say the info these pals spout out is consistently bogus, but sometimes the claims being made merit a little additional checking, simply because they sound outright false!

One such “fact”/fact/fact*, is that when it’s hot out, you’re actually better off drinking a warm beverage than a cold one if your goal is to cool off. During the summer months, this claim is made essentially any time coffee is being procured, and it’s especially potent if there is a New Englander (these people have deep cultural ties to iced coffee, apparently) present, because it really riles them up.

Ask the bestower of this information why hot coffee cools you off on a hot day, and chances are, they won’t know. (The thing about trivia, is that the holder of the correct answer doesn’t need to know why it’s correct. Being a pub quiz champion doesn’t automatically grant you a PhD.) A couple of minutes later the coffees – iced and hot – are in-hand, and everyone’s moved on. Next time a coffee hang is in the cards, if it’s warm enough, the cycle will repeat.

We’re here to break the cycle.

Cold drinks: a cultural phenomenon

Let’s start by addressing that the small but vocal pro-hot-drink-in-hot-weather crowd in America is part of a much larger global school of thought. It’s extremely common in India, for instance, to consume hot tea on a hot day – and India experiences plenty of hot days. It’s common in China to start the day with a warm glass of water, and plenty of Chinese cities boast summers as soupy as anything you’ll encounter in the States. Between those two cultures alone, that’s roughly 3 billion people who ascribe to this philosophy.

So right off the bat, if you’re an American and reaching solely for iced beverages to combat soaring temperatures, you’re outnumbered. Not to say conventional wisdom should be confused with rigorous scientific inquiry, but on a truly global scale, common sense is probably more in-line with opting for a warm or at least room temp drink during a heat wave.

America’s infatuation with iced beverages is somewhat unique. Travel abroad, and if the water you request at a restaurant contains any ice at all, you’re looking at one or two little cubes spinning slowly and serenely as they melt away into the drink. Visit an eatery in the states, and the water you’re presented with upon arrival could more accurately be described as a cup of ice with a splash of water thrown in for good measure.

 And it all started about 225 years ago. In the early 1800s in New England (those iced coffee roots run deep, as stated earlier), industrious Americans began harvesting the region’s ample ice and shipping it to warmer climates, where it would be used to preserve food, keep medication from spoiling, and even to cool homes.

Looking to increase profits, early ice barons next aimed to incite demand for ice where there wasn’t – for human consumption. By suggesting people add ice to previously warm or room temp bevs, and even providing free samples, ice mongers cultivated America’s cold tooth. 

Technology improved over time, and by the mid-1950s, at-home ice makers were becoming increasingly common. No longer did you need a multiple-ton block of ice chipped away from a frozen pond in exurban Boston to chill your drink. And the rest is history. We’re more or less still addicted to the stuff.

Neat. But are hot drinks actually better at cooling you off than cold ones?

As with all seemingly simple questions posed in this – and most nutrition blogs that strive for honesty! – the answer is a bit nuanced.

 An often cited study suggests that a warm drink can help your body more effectively lower stored body heat… under the right conditions. The study involved nine male cyclists, who were actively cycling while ingesting water at varying temperatures. A different study took a look at the effect of ice slurry consumption during exercise, and found that respondents reported feeling cooler, but that their internal temperature remained unchanged.

Basically, it comes down to sweat. Your tongue, esophagus, and stomach contain receptors which are part of the complex system that detects warmth and triggers your body to sweat. A warmer beverage will be recognized by these receptors as such, and tell your body to sweat more profusely than it otherwise would given the atmospheric conditions.

As long as the excess sweat your body is pushing can actually lead to evaporative cooling – variables that might impede this process include high humidity, the presence of clothing, and general air flow – then the hot beverage will in fact lead to a greater cooling off of your body than a cooler one. Of course those are very common variables to experience… 

So our takeaway? Studies on the subject tend to be very small in scope and athletic performance oriented. Ideal conditions for evaporative cooling via sweat are hard to come by – if you’re reading this in a swimsuit on a shaded patio in Phoenix, Arizona, with an industrial fan blowing directly at you, nicely done – so in conventionally hot conditions, we’re going to suggest drinking whatever temperature of beverage you enjoy most, so you’ll drink more of it. That’s the best way to stay cool and safe in the summer months. 

And besides, coffee contains caffeine, which is a diuretic, meaning it makes your body expel water and sodium more quickly than it otherwise would. The real power move at the coffee shop, as far as hydration is concerned, is an herbal tea – hot or cold.