Green’s Dictionary of Slang

1. (US) a frankfurter, a hot dog.

1886		St Paul Dly Globe (MN) 11 Apr. 6/2: Never did red hots meet such a ready sale or command such prices, and the real red-hot man would have made an independent fortune.
1890		Salem (OH) Daily News 18 Jan. 4/1: The red-hots were generally cut in two longitudinally and smothered in mustard.
1900		Daily Register (Decatur, IL) 16 Feb. 8/4: Tom Busby, the red hot and tamale vendor at Bradley Bros.’ corner, had some of the reddest hot red hots that the Decatur market ever knew last night for a short time. The fire department had to be called to cool them off and then Tom went out of business.
1913		Day Book (Chicago) 20 Aug. 13/2: I have sunk my teeth into the haunches of one of those Coney Island red hots.
1917		R. Lardner ‘The Facts’ in Coll. Short Stories (1941) 461: ‘What odds?’ ‘A good lunch against a red hot.’.
1922		Ogden Standard Examiner (UT) 15 Feb. 3/5: Bill of Fare is Red Hots and cabbage.
1936		J.T. Farrell World I Never Made 20: Don’t spend it all on pop and red-hots.
1946		J.E. Dadswell Hey, Sucker 77: They want to eat [...] popcorn and red-hots.
1962		C. Clausen I Love You Honey, But the Season’s Over 131: Get your red hots. Ice-cold drinks here.
1971		B. Malamud Tenants (1972) 131: I got this redhot with mustard on it.
2018		(con. 1963) L. Berney November Road 233: [He] cooked hamburgers and red-hots on a portable charcoal grill.

2. a small, cinnamon-flavoured sweet.

1913		J. London John Barleycorn (1989) 108: Nita, who sold us red-hots at the candy store, was a friend of Ruth.
1937		E. Anderson Thieves Like Us (1999) 166: She used to [...] bring a big old sack of red-hots.
1965–70		in DARE.

3. (US) a gangster.

1923		T.A. Dorgan in Zwilling TAD Lex. (1993) 59: I waited on that red hot — He’s no bargain — He always has the exact change for the bad news.
1933		R. Chandler ‘Blackmailers Don’t Shoot’ in Red Wind (1946) 74: On your way, red hot.
1949		R. Chandler Little Sister 120: She didn’t have to shack up with a red-hot.
1950		Goldin et al. DAUL 176/1: Red-hot, n. (South, scattered) 1. A thief; crook. [...] 2. A gunman or professional killer.
1953		F. Brown Madball (2019) 55: Charlie was a red hot, a moderately big time gangster.

4. (US black) a highly aggressive, volatile person.

c.1935		‘Mae West in “The Hip Flipper”’ [comic strip] in B. Adelman Tijuana Bibles (1997) 90: She’s an overheated red hot / And here she comes – Mae West.
1983		R. Klein Jailhouse Jargon and Street Sl. [unpub. ms.].

5. see hot mama n.