What is the best way to treat a virrus

Depends on what kind of virus it is. If it is a sore throat virus, for example, a medicine like antibiotics would be enough. If you have cancer though (no offense, just making an example here), you would have to go through surgery, or other "harder" methods.

If it's a smaller child or infant, place one on the middle of the chest and on the child's back. (if it is a bigger child with enough room for two, place one on the upper right/your left of the chest, and one on the lower left/your right) the pads should never touch each other.