best way to keep fever down?

Harleigh

I'm watching my boyfriend's son while he's at work.. well when he gets a fever, he's very very prone to having seizures.. we just woke up and his forehead is pretty warm.. unfortunately we JUST moved and i dont have a thermometer to see what his exact fever is.. i just gave him some children's ibuprofen, not sure how long that will take to lower the fever.. what else can i do to lower his temperature that will work quickly?