First, I recommend to get a thermometer so you can know if your baby is having fever or not. My baby's pediatrician recommended us to get Terumo. Its expensive (RM70+) but its suppose to be really accurate. So I guess its worth it.

If you suspect that your baby might be sick and needs immediate attention, I would suggest to send him/her to hospital. There is always a place where they handle emergencies. Its open 24hours. If necessary, they will contact your baby's pediatrician informing them about the emergency (if the pediatrician you go to is in the same hospital)

hope this helps

well, TS mention that it was during the baby's full moon. So based on my personal experience of new parent and new baby, piece of mind (without the need to guessing if we did the right thing or not) is very important. That was why I recommended to go to the hospital when in doubt.