You can STILL give him tylenol &/or ibuprofen to ease the achiness/ pain/ discomfort. 1 will get you 50 he also has a headache (don't you usually when you have a cold?).
Personally, I treat the symptoms (cough syrup for coughs -dextromathorphan and/or guaifenesin , pseudoephedrine for sinus and lung congestion, tylenol and/or ibuprofen for aches and pains w/ or w/out fever), push fluids, and encourage rest (aka no trips to the park or active play, but bed and reading or couch and movies). If there's no improvement with rest, fluids, and meds (meaning he doesn't need them anymore, not he feels better while on them)... or if anything changes for the worse... I take him in.