102.3 isn't that high for his age, and he's probably fine. My (also 1 year old) son just had a 102 fever a couple weeks ago. I've found that Advil (ibuprofen/Motrin) works better than Tylenol, obviously use the infant kind; I've also found that a full dose isn't usually necessary.
If Advil or Tylenol doesn't bring the fever down, or he has other worrisome symptoms (signs of dehydration, obvious pain, more lethargy than you'd expect in a sick child), then it's time to call the doctor. My son's pediatrician told us not to bother bringing him in unless he hit like 104 :)
Also, you have to trust your gut. You know your child better than anyone, and you can tell if he just seems "not right". When my son had his fever a couple weeks ago, I never worried at all because aside from the fever and some rough teething, he was himself. He was fine within a few hours. (Well he had a cold for the next week, but was otherwise ok.)
Hopefully by now your son is fine and you don't even need this response anymore :)