Para el frio...

 

"Brr" 

"Brr is a set of heaters especially prepared for cold, winter days. Heater "Brr" insulates hands from the hot cup, keeps the heat and warms frozen hands. "Brr" is made of  wool. There are two silicone band inside the heater to prevent it from sliding down the cup"

via: http://www.behance.net/gallery/Brr/642855