Febrile Seizure
A Febrile Seizure is often related to a sudden spike in temperature. It only lasts a short period of time, but during that time, the symptoms are scary. Convulsions, lack of responsiveness, eyes rolled back and staring blankly at the ceiling.
Our son had one last night, and it's a scary occurrence, let me tell you, especially for folks like us who have never heard of it before.
I called 911 for the first time in my life, made sure they knew how to get to my house (it's a new street, so I grilled them on the location to make sure they had it right - they did), and the 911 operator did a great job of asking questions and giving us instructions, and eventually said that he'd likely experienced a febrile seizure and that a paramedic would be here shortly, and then he let me go.
So the next step: Google It.
It was a huge relief, even before the paramedics arrived, to know that what Matthew was experiencing was not serious, relatively common, and had no serious long term consequences.
He's still got a bit of a fever but he's doing much better today.