Paddy walks into a camping goods store to purchase a thermos. He walks to the shop keeper and says "Hello there. I'm looking for a thermos to take into work".. The shop keeper hands him a shiny new thermos from behind the counter. "This one, keeps all your hot stuff hot and all your cold stuff cold" says the shop keeper. Paddy is sold on this, and walks out to go home with his proud new posession. Next day at the work site, Paddy brings out his thermos, much to the awe of all his fellow workmates. "Thats fantastic" they all say, "but what does it do" "It keeps hot things hot and cold things cold" says paddy, quite pleased with himself. "Whats it got inside then Paddy?" they all say. "two cups of tea and an ice cream" says Paddy.