My son has a febrile seizure when he was a toddler as well. He had a high fever and the doctor said the seizure was caused by the fever spiking. It is frightening, but not harmful according to the doctor. The key is getting the fever down and you did that by being attentive and a good mom. You did all the right things.

By the way, my son never had another seizure and he has had many many fevers since.