Before you leave for the playa resign yourself that your hair will become a mess that resembles a scrub brush more than hair. If your hair is long, things can be even more grim. If you manage to come back to the default world with hair that can be salvaged without cutting most of it off, consider that a bonus.

The playa is absolute hell on hair. Mathematically this can be represented as:

Sun + heat + extreme dryness + wind + alkaline dust + reduced showering ability = some nasty mess on your head.

I normally have relatively short hair and within 2 days every hair on my head is stiff as could be and standing straight up. My facial whiskers by the end of the week are all standing straight out from my skin, stiff as a broom bristle and had all turned pure white.

Keep in mind that any showering on the playa will of necessity be limited and short so long shampooing sessions are not likely to be part of your reality.

Long Hair

Those with long hair can have even worse issues - the combination of the elements (especially the wind) may turn long hair into playa dreadlocks. I personally find playa dreadlocks really sexy on a woman, but it may be difficult to go back to work in the default world looking like that.

Although I have no experience with long hair on the playa personally, the following strategies are said to help:

Post Playa Care

As soon as possible wash your hair with moisturizing shampoo. Then do it again. Conditioner helps too. After a few days of this your hair may attain some semblance of its pre playa state - but don't count on it.

No hair gel is needed after a day or two. This photo was taken on the 13th playa morning while getting ready to depart and my hair pretty much feels like steel wool, has faded from deep purple to pink, and is dying for a good long shower.