Definitions by Professor of Poop Euphemisms
Hot nickel
What your anus feels like when you have to defecate so immediately that the fecal matter is almost protruding from your body. The phrase "sitting on a hot nickel" is synonymous with "have a turtle head poking," "prairie doggin' it," and "touching cloth."
Hot nickel by Professor of Poop Euphemisms November 1, 2013