Second Wind

You can cast this spell only when you have fewer than one-quarter of your total hit points. With a gasping utterance, you summon invigorating air to fill your lungs. You heal 2d8 points of damage + 1 point per caster level (maximum +10). You can cast this spell either as a swift action on your turn or as an immediate action when you are brought to below 0 hit points. If you do not breathe, you can’t benefit from this spell.