Boy, it’s hot out there.
“Summer temperatures in the Tennessee Valley are sweltering,” the Tennessee Valley Authority warned its electricity customers. People in Wise, Virginia, taking advantage of the Affordable Care Act while they could, lined up during what The New York Times called a “sweltering day” and the Southern Poverty Law Center called “sweltering heat.” Immigrants being smuggled into the United States died in the back of a “sweltering truck,” with the survivors enduring “sweltering hell.”
Those are just the adjectives. “Sweltering” can also be an adverb, or a noun (though, if you want to be technical, “sweltering” as a noun is really a gerund, which is a verb pretending to be a noun).
Of all the ways to say that it’s oppressively hot, “sweltering” or its other forms are among the most popular. It’s not one of the most looked-up words on dictionary sites, indicating it’s common enough that no one needs a definition or explanation.
Unless you die, however, you’re not being true to “sweltering.”
The first appearance of any form in English is around 888, the Oxford English Dictionary says, in the form of the verb “swelt.” It meant “to die, perish.” It came into English from several places, including words without direct relationships to heat. The Old Norse version, for example, was “to put to death, die,” the OED says, while various Swedish and Danish words meant “to starve.” Old Germanic words meant to “burn, languish,” but referred to passion, not physical heat. “Swelter” could also be descended from an Old English word, “sweal” or “swale,” which meant “to burn.”
But the heat was on. From the original “swelt” in 888 arose the verb “swelter” around 1400, the OED says, meaning “to be oppressed with heat.” That was quickly followed by the noun “sweltering,” but the adjective and adverb didn’t show up for another hundred years or so, when they were used to refer to things exuding heat, rather than suffering from it.
“Swelter” as a verb can be transitive or intransitive, meaning you can oppress something with heat, or you can be oppressed by heat.
“It’s a swelter out there,” a Virginia columnist said, using it as a plain, ordinary noun, the most recent entry in the swelter wars, seen only since 1851, according to the OED. It’s also the least common form we see today.
If it’s “sweltering,” must it be humid as well as hot? Only the American Heritage Dictionary thinks so, according to its definition. Just about everyone else is cool with the idea that you can “swelter” in the “dry heat” of Phoenix just as easily as you can in swampy New Orleans.
That we can use “sweltering” in so many ways is a testament to the malleability of English. But despite the similarity of sounds, “sweltering” and “sweating” are unrelated, etymologically at least. Yes, you may do both in the heat of the summer, but there’s no need to pile it on. And because “sweltering” burns by its nature, you can turn off the “heat” in its company.