Heat is form of energy which causes in us the sensation of warmth or coldness. Have you touched a warm glass of water or held an ice cube ? You will fill the heat of the warm glass of water and the coldness of the ice cube. This is because heat energy is transferred from the warmth glass to your hand ; so your hand feels warm. When you hold an ice cube, heat energy is transferred from your body to ice. So your palm feels cold. This transfer of energy is always from a body at a higher temperature to a body at a lower temperature.