Question about heightened powers

[ZenCloud]

When reading a power (for example Dragon Claws pg. 218), how do you calculate when the power is heightened? Dragon Claws states:

"Heightened (3rd) The claws count as +1 magic, granting a +1 item
bonus to attack rolls and adding a damage die; you gain 7 resistance."

Does this mean the power is heightened when the caster reaches character level 3 OR when the caster is able to cast 3rd level spells? Thanks in advance @o@

[CommanderCoyler]

Bloodlines, p129 wrote:

Like cantrips, bloodline powers are automatically heightened to the highest level of spell you can cast.

Works the same for powers from other spellcasting classes. Non-spellcasters (and powers from sources other than spellcasting classes, including multiclass feats) heighten their powers to a spell level equal to half their level.