When a person is having a convulsive seizure (or you know/they have indicated they are about to), gently roll them on one side (to allow any fluids to drain out of their mouth and keep their airway open), support their head, remove any dangerous objects nearby (including their glasses), and time the seizure.

If a seizure lasts longer than five minutes, call 911.

"Seizures usually end within a few minutes and keeping a person safe from injury during a seizure and paying attention to the seizure duration are the best first aid," Dr. John Stern, director of the Epilepsy Clinical Program at UCLA, tells BuzzFeed. "If a seizure is longer than five minutes, then the risks may be greater and emergency care may become more important. If a person is not known to already have epilepsy or has a complicated medical condition, then emergency care may be needed sooner.”

For other types of seizures, it is important to remain with the person, gently guide them from danger (but avoid restraining them), and call 911 if the seizure lasts longer than five minutes.

For more on how to care for someone during a seizure, check out this video featuring Star Trek stars Zachary Quinto and Chris Pine for Talk About It.