I was taught in my Physics lessons that the hotter an object is, the quicker it looses heat. My plumber reckons that it's cheaper to keep the hot water on all day rather than heat it and let it cool if it's not used. What's the better way? Keep the water hot, or let it cool, and then heat it on demand?  

i've been wonding about this for a while now, and decided to look here for an answer,

i play in goal for a football (soccer) team, and while playing in matches, often in the wind and rain, i often find myself getting cold/wet. Are there any positions that i can stand it to minimise the ammount of me getting wet, cold etc.

I order a coffee in Planetbucks. It comes as a cup of black coffee and a little jug of cold milk. I decide to postpone drinking it for 5 minutes. Should I put the milk in immediately or just before I drink it in order to have it as hot as possible?

Surely if they are good conductors then they will absorb the heat easily, just as they do when you place your hand onto the surface?

If you think about it you can't lose heat in a vacume because molocules have nothing to transfer heat energy to. Unless space isn't a total vacume...