Deep Breath

The recipient of this spell can breathe and function normally in thin oxygen, suffering no ill effect at altitudes up to 30,000 feet. If more than one creature is touched during casting, the duration is divided evenly among all creatures touched.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the duration of the spell increases by 2 hours for each slot level beyond 4th.