First, we must understand that an attack is unpleasant but not dangerous, so we shouldn't panic. We should remain calm and simply be there for the person, offering them whatever they need. For example, you can remind them that the sensations are unpleasant but not dangerous, that it will only last a while and the anxiety will subside, and that you are there for them. Some people will ask for physical contact, others will want to be left alone. At that moment, it's important to respect their needs, and once the attack has passed, you can talk about what happened. Being overprotective doesn't help, but neither does being too rigid or forcing the person to act in a certain way.