The New York City-based television program Late Show with David Letterman contained the segment “Top 10 Signs It’s Too Damn Cold” on January 19, 1994, and this was Number 6:
 
“Times Square hookers charge $20 just to blow on your hands.”
 
The joke—often told about hookers in places other than Times Square—has been printed on several images.
 
                 
Wikipedia: Late Show with David Letterman
Late Show with David Letterman is an American late-night talk show hosted by David Letterman on CBS, the first iteration of the Late Show franchise. The show debuted on August 30, 1993, and was produced by Letterman’s production company, Worldwide Pants Incorporated and CBS Television Studios. The show’s music director and leader of the house band, the CBS Orchestra, was Paul Shaffer.
 
21 January 1994, The Evening Sun (Baltimore, MD), “Top Ten Signs It’s Too Damn Cold,” pg. 17A:
6. Times Square hookers charge $20 just to blow on your hands.
 
22 January 1994, Orlando (FL) Sentinel, “Letterman’s Top 10,” pg. A2:
Top 10 signs it’s too damn cold, as presented on Late Show With David Letterman: (...) 6. Times Square hookers charge $20 just to blow on your hands.
   
Google Groups: alt.smokers.cigars
Re: Damn, it’s cold
Miss Elaine Eos
1/15/09
In article , Ray

wrote:
 
> It’s so cold here in the midwest, hookers are offering to blow on your
> hands for $20.
 
Twitter
Lance Sanders‏
@Lancebowski
Replying to @redeyechicago
@redeyechicago It’s so cold, the hookers downtown are charging $20 just to blow on your hands. G’night, everybody!
9:26 AM - 15 Jan 2009
 
Twitter
WeirdRalph‏
@weirdralph
New Yorkers are getting hit hard by the cold weather. For instance, hookers are now charging $20 to blow on your hands!
7:35 AM - 8 Jan 2010
     
Google Books
Flat Spin:
A Cordell Logan Mystery
By David Freed
Sag Harbor, NY: The Permanent Press
2012
Pg. ?:
“My next door neighbor’s a vice cop. He said the hookers downtown are charging twenty bucks just to blow on your hands.”
 
Google Books
Cries from the Deep
By Anthony Hulse
Lulu Press (Lulu.com)
2015
Pg. ?:
“It’s that cold, the bloody hookers in Soho (London—ed.) are charging a tenner just to blow on your hands,” joked a red-faced, obese man, wearing a flat cap and serving his customers.
 
Twitter
John Kozak‏
@JohnKoz09610153
Replying to @brithume
It is so cold in Detoilet the hookers are charging $20!dollars to blow on your hands 😈
6:56 PM - 6 Jan 2018