Hair conditioners

Sometimes called "deep conditioners" or "reparative masks", these temporary leave-on hair products can work even better when they're allowed hours, not minutes, to absorb deeply into the hair shaft. Before bedtime, massage the mask along the ends and mid-shaft of dry hair and comb through. Rinse and style as usual in the morning.

Antiperspirant

Some extra-strength antiperspirants are specially formulated for nighttime use, but a regular formula can also be more potent during the night's optimum conditions. "For people who have problems with excessive perspiration, it makes a lot of sense to apply an antiperspirant before you go to bed," says Kleinsmith. "When you're not already perspiring, you can block the sweat glands more easily and let the medication work more effectively."