My grandson has temp of 101.8 he has a bit off a cough and slight runny nose, should we give tylenol (acetaminophen) or call the dr.or wait?

It depends: A fever is not dangerous. It's a sign that he is fighting something off. If he is only mildly sick and over 3 months old, give the tylenol (acetaminophen) or Ibuprofen (one or the other, not alternating), get the fever down and see how he feels. If he perks up, eats or drinks some, plays a little, you can watch him for a day or two to see if he fights it off. If he looks sicker, get him seen by the doctor.