I usually take Advil when I feel a cold coming on, sometimes I'm quick enough to nip it in the bud, and the cold doesn't fully materialize, other times I'm ill for a few days.
When my kids start with a cold, I give them liquid calpol, which is basically a child's strength paracetamol, it's used in England from a baby upwards, for all childhood illnesses, plus teething., but it does tend to make them sleepy, but works well.