It can get up to 105F during high noon, though the past year it wasnt all that hot at all (in fact there were rumors of rain!).
But because it's in the desert, it then drops down to 50-60F during the evening, and sits nicely in the 70's/80's during the sunset hours.
If you wear cool clothes, stay hydrated, and arent in the direct sun for all too long, you'll be fine.
Also, only two stages are in the direct sun. There are three tents, though if the tent is packed it can get pretty hot in there, even at night.
For drugs and alcohol, you just have to have your wits about you. Dont get plastered during the day, and dont get TOO plastered at night.
and the Do Lab is always there to cool folk down, and listen to some amazing artists while you're at it!