The Heart Medal is an item obtained in Skyward Sword. While Link carries this item, enemies will drop Recovery Hearts more frequently. He will also find hearts more frequently when cutting down grass, digging in holes, etc. This will be very handy for Link if they are having a hard time fighting enemies. There are two Heart Medals, which can be found in Goddess Chests from Goddess Cubes.
First Heart Medal
The first Heart Medal's Goddess Cube is in the southwest of Lanayru Province. Link must defeat an Ampilus with a Bomb carried by the Hook Beetle, and then ride its shell across the sand until he is close enough to run to the cube's platform. Once he activates it with a Skyward Strike, Link can find the corresponding chest on an island in The Sky, east of Lanayru.
Second Heart Medal
The second Heart Medal's Goddess Cube is also in Lanayru, this time in the northeast. Link must use a bomb on a cracked wall to open a passageway. At the end of the passageway, he will find a chest with a Piece of Heart and a canyon filled with sinksand that must be crossed using the Clawshots. At the end of this passage is a platform with the cube on it. The chest is found in a pool filled with water on a floating island to the west of Beedle's Island. Link can use the Water Dragon's Scale to dive down and then leap out of the water to find it.