My 3 year old has had a fever now for 24 hours straight we have been giving him Advil and tylenol (acetaminophen) on and off. Should we take him to the dr or just try and ride it out?

How high? You do not mention how high the fever is. If you have a temp that is less than 100.5 rectal, and your child otherwise looks good, i would try to give him a tepid bath and maybe some popsicles. Low grade temps are part of the immune system trying to fight off an infection. I would not recommend alternating Motrin and tylenol (acetaminophen) for this. Any other symptoms? If you have any concern go to the dr.
Be seen. It is reasonable to alternate advil and tylenol (acetaminophen) every 4 hours through the night, but if that is not controlling his fevers, then he needs to be seen.