Short answer: there is no difference in the cooling capacity of the stem between a nose warmer and a long canadian.
Long answer comes from http://www.neatpipes.com/blog/built-for-comfort-a-short-history-of-the-chubby-style/&id=7
The Thermodynamics of Chubby Pipes
So let’s assume you’ve come this far and are intrigued by the idea of chubby pipes: you like the notion of comfort over conflict, you like the idea of cool-to-the-touch pipe bowl walls, you like the look of fat stummels, you like the “Shazam! Ain’t that different?” sensation. But you’re still afraid of one thing: won’t short pipes smoke hot? Isn’t that why Canadian pipes have long stems? I myself was worried about this self-same problem once upon a time, and I can assure that It Is Not So. But what you really need is an authority, an Auctoritas to school you, so I put in a call to my Pipe Sensei, Mr. Rainer Kockegey-Lorenz.
Rainer works for one of those big strange corporations who do sci-fi things like optimize industrial minerals and implode the molecular structure of various fungi to refract flame retardant polymers. I think this has something to do with saving the world (he’s always fuzzy on that pont), but it has certainly enabled Sensei RaiKo (as he is known by his disciples) to live a pipe-and-tobacco-filled life. Here is what he wrote to me—completely uncensored, as per Doc Irwin’s instructions (“the truth will set you free”):
SENSEI RAIKO: It is in fact hard for puny mortals like yourself to believe that a 600°+Fahrenheit fire which enters the oral or mouth cavity (which is bounded laterally and in front by the alveolar arches [containing the teeth], and posteriorily by the isthmus of the fauces) at a distance of less than 100mm (or 4”) can arrive as cool smoke. You of course are under the polar yet equally absurd delusion that a 180mm (or 7”) long-shank Canadian would by its very length deliver a cool smoke. In both suppositions you are wrong wrong WRONG.
In point of scientific fact, the coolest place (depending on your particular puffing habits of course) is where the smoke enters the airhole. Now imagine (if you can) the small volume and cross section of the air hole to the bit area on a pipe and you automatically have the answer: it cannot appreciably cool in the space of those 80mm (or 3”).
There is of course literature available on such things, studies which have placed thermocouples at different sections of the shank and stem, but I think they are way above your cognitive ability. But with assistance you may understand Robert F. Winan’s excellent chapter “Reflections on Tobacco” in The Pipe Smoker’s Tobacco Book (1972), pp. 58-62. As you can see from the graph below, the temperature profile of the smoke at less than 70mm (or 2 ½ inches) behind the bowl—[in other words, the exact length of the new Chubby Saddle Billiard’s shank!—ed. note] ranges from 85° to 118° F with an average temperature of 96°. This is less than your body temperature, Charles. Do you begin to get the picture or shall I use finger paints?
TEMPERATURE PROFILE OF PIPE SMOKE ENTERING THE MOUTH
It’s always astonishing to non-scientific morons (such as yourself) to realize that the smoke temperature arriving in your mouth is at nearly human body temperature—as Winan says, “if coffee were served to you at this temperature you could gulp it down without hesitation and then complain about being served tepid coffee” (60).3 What “bites” is not the heat of the smoke, but mainly the alkalinity of the smoke in your tobacco.
CHARLES: So the short shank doesn’t figure into how hot the smoke is?
SENSEI RAIKO: What have I been saying?
