I found a wild baby bird alone and shivering. How can I help?

His best chances will be to stay with his parents. If you can see where the nest is, you may briefly pick him up to place him back in the nest. Most birds do not actually have a very good sense of smell, so your scent won't cause a problem - however, your presence will frighten the parents away. If you cannot return him to the nest, the best course of action depends on how old he is.

If he's got feathers and can hop, he's probably a fledgeling who is learning to leave the nest and you should leave him alone. If he's just starting to get his feathers and seems bright (can lift his head and look around), make sure he's in a safe spot (you can make a little nest on the ground with a clean towel in a small box - but don't move him far from where you found him, so his parents can find him there too) and see if the parents come to feed him.

If you're convinced he's on his own, or if he's too little to have any hope of surviving on the ground (even if the parents stop by to feed him), then I recommend finding your closest wildlife rehab location and calling to see if they'll take him.

Hope this helps!