WWYD? sick baby

DS is 10 months old. He woke up this morning very warm and with a temp of 100. Loosened his clothes, gave him some water and a bottle. About 20 minutes passed and I took his temp again and it was 101.6. Gave Tylenol (store brand). His temp hoovered in the 100 range after Tylenol. The fever wasn't even what bothered me (since it wasn't that high to begin with), it's the significant lethargy. He is awake only long enough to have 2/3rds of his bottle, get a diaper change and then he wants to go back to sleep. He has fallen asleep on me 3x, on his playmat 2x, etc and this is not typical of him. I took him to the doctor. His lungs and ears are fine. No stuffy nose. Told me it was likely a virus and to wait it out. The ped may be right, but what bothers me is that I've seen him through pneumonias, RSV, ear infections, pink eye, colds...I've NEVER seen him lethargic like this. The fact that the fever doesn't go away with ibuprophen is curious to me too. Almost everyone I talk to says wait it out. My parents think we should bring him to the ER...I'm thinking PM Pediatrics since they are so thorough and have all the equipment there anyway and without the wait. WWYD? Would you wait it out knowing that the lethagic baby who couldn't muster the energy to even crawl to a toy today and who normally is so talkative barely could speak more than a couple of babbles and whining doesn't even resemble how your child typically acts? Would you go to the ER? Or would you just get a second opinion at PM Pediatrics?

Wanted to add that since going to the Ped he's been on ibuprophen instead.

Re: WWYD? sick baby

You just described DD today, who is also 10 months. the daycare called us saying she had a fever and was throwing up. DH took her to the ped and it is a double ear infection but also said a virus is going around. Keep hydrated and go to the ped.