Today, I read a short essay from a magazine about how to preserve the coffee as hot as possible in a short time (if you don't want to drink it right away) by adding the cream in to it as soon as possible. It reads: if you add the cream soon, some amount of heat being transferred to the cream so the temperature b/w the coffee and air will be decreased, this is also make the convection process slower. I am thinking ... what about the sugar? In this sense, should I also add the sugar asap (without stirring of course)? And of course, if I use a black cup instead of light-color one, it will also help to preserve the temperature a bit due to radiation, right? What about the color of cream, will dark one better than light one?