Ensure the victim is safe until the seizure comes to a stop, notes the Centers for Disease Control and Prevention. Clear the area around the victim so that he doesn't hit any sharp or hard surfaces. Remain calm, and urge others around to do the same.
Lower the victim to the floor, and put a flat, soft object such as a folded sweatshirt under his head. Take off any scarves, neckties or other items around the neck. Allow the person to move freely, and keep moving any sharp or hard objects out of his path, reports the CDC.
Do not try to open the victim's mouth or keep him from swallowing his tongue. The belief that seizure victims swallow them is not correct, according to the CDC. However, when possible, turn the person onto one side to keep his airway free of obstructions. Wait until the seizure has ended on its own and the victim is fully awake. As he returns to consciousness, talk in a calm, friendly voice.
Offer to contact a relative or friend, or at least to call a cab, to help the victim get home if he appears confused or in need of help. Call 911 if the victim appears to have an injury, pain or difficulty breathing, or if the seizure lasts longer than five minutes, advises the CDC.