Originally Posted by cyccommute

Adding sugar, ethanol or salt does little to depress the freezing point in concentrations that you could consume. To depress the melting point -10C would require a solution that is 5 molal for a single particle solution like ethanol or sugar while it would require a 3 molal solution for a 2 particle solution like sodium chloride. A "molal" is a mole of a substance per liter of solution.

Sugar, for example, would require 5 moles of sugar per liter of solution. That's 1700 g per liter of solution or a bit over 3 pounds of sugar. For ethanol...100% ethanol, not the 35% in vodka...200 g of ethanol per liter or about 20% total by weight. How many shots of vodka can you drink in one sitting without geting blind drunk. Finally, for salt, you'd need around 180g of salt per liter or 18%. That's edging up into toxic salt levels. It certainly wouldn't be good for you over even a short period of time.