Christmas Tree

Granny Lea brought us chocolates for the tree.

Holly and Rosie: "Daddy can we put the chocolates on the tree please?"
Daddy: "Sure. You pass them to me, and I'll hang them on."
Holly and Rosie: "Aw... Can't we do it?"
Daddy: "Sorry. They have to be quite high up. Or... they melt."
Holly and Rosie: "Really?! Why?"
Daddy: "Er... Underfloor heating."