Toddler fever seizure

Last night my 1 1/2 year old had a seizure due to a spike in fever
Has any other mamas been through this with their child, im really scared it's going to happen again so me and my fiancé have been checking his temp every 1/2 hour. 
I'm worried that the 2-3 minutes he was having the seizure may have caused brain injury that we can't see yet. 
I've never been through something so terrifying, not knowing if your child is going to die is the most horrible in the world. :(