the infection symptoms include rollercoaster fever + cough with phlegm + running / block nose + rashes. its contagious so you might want to use mask for you n your family member since the child is too young to want to have their face covered up.
for fever, you might want to consider sponging him, sponge means dip washcloth into tap water and then squeeze left a bit damp then wipe the forehead, neck, groin wth the towel. but for me i dont want to wipe the groin, so i just wipe the forehead and neck. then sponge for around 2-3mins then you can stick the cool fever gel on his forehead. and also dont forget to regularly take temperature and timely eat the fever medicine .