If you're outside and you notice your hair or someone else's hair standing on end, take immediate action. Before lightning strikes, positively charged material like hair is sometimes pulled upward toward the negative charge in the sky above. When this happens, you may only have seconds before a lightning bolt strikes. If you can run indoors quickly, do it. Otherwise, crouch close to the ground with your feet pressed together, wrapping your arms around your knees.
Taking this evasive action will accomplish two things. By making yourself smaller, you may encourage the lightning to strike another, more convenient object. And if the bolt does aim for you, there's a much better chance that it will pass through your body and into the ground without causing as bad of an injury.