Fluids and rest
Same as what's best for you.
The body's immune system does great clearing cold viruses; we do best when we help it do its job using lots of fluids, rest, raising the head of their bed at night, running
a cool mist humidifier
, nasal saline drops. Use bulb suctioning to clear their nose. Mild fevers actually help fight the cold; don't stop fever
if it isn't making them miserable & isn't too high.