1657 (pre): The Flaming Drunk
In 1657, Thomas Bartholin published an account of a person dying due to an eruption of flames from their mouth that occurred during or after a drinking match with strong liquor.
The Original Source
From what I've seen, all modern versions of the brief account above starts with Pierre-Aime Lair's famous study entitled "On the Combustion of the Human Body, produced by the long and immoderate Use of Spirituos Liquors," published in French in 1798 and in English in 1800. Lair presents this account thus (I've highlighted the bit we're interested in):
“We are told by Thomas Bartholin [First century.], on the authority of Vorstius, that a soldier, who had drunk two glasses of spirits, died after an eruption of flames from his mouth. In his third century Bartholin mentions another accident of the same kind after a drinking-match of strong liquor.”
As you can see, the account above is simply described as being like another account he mentioned (a link to that other account is below, if you're curious). Now the fact that everyone has taken their version of the story from the passage above is interesting, because Lair tells us what his source for the story was... yet no one I've found seems to have gone back to look at the original source, Thomas Bartholin's "third century." I've found a copy, so let's see what this account actually says.
The Man in the Street
The Latin in Bartholin's account is not an easy translation, and much of the incident must be read in context of what the section the story appears in is about... which is drunks that die by mysterious fire. In discussing this matter, Bartholin states that a man had been found dead near the author's house recently whose state was an example of the fires he was discussing. This man had spent the whole night in a local tavern, and had consumed a huge amount of alcohol; and he had stumbled and died in the street shortly after leaving the shop. And this is exactly where the translation becomes somewhat vague as to the remaining details, but seems to strongly imply that either the cold weather or the cold of the street itself had apparently extinguished a flame that had projected from this man's mouth... so presumably, the man was found dead with burns in and around his mouth, as it seems the actual flame may not have been witnessed.
Given this happened near Bartholin's house, it's possible that this incident could be the very reason that Bartholin later did his studies regarding possible cases of spontaneous combustion in humans.