Very worrying.
This bird should only be out of the brooder to eat and then go back in. They should not be on your shoulder.
No feathers = they can´t regulate their body temperature. If they get cold, it can lead to crop stasis.
Need to be in a brooder.
Be sure you are feeding the formula on a spoon at 105F. Boil water, then allow to cool a little. Make the formula. Put the thermometer in and wait ´til it cools to 105.
Never re heat old formula. Make fresh every time. Be sure to mix well removing all lumps.
Have a read of this thread;
There´s tonne of info on there incl. videos and a chart to keep records.
With these Links-I hope to bring You as Much information as I can to help anyone that finds them selves having to Hand feed A chick Lots of tips for Breeders-with links for Hand feeding etc http://www.parrotscanada.com/breeder...rbreeders.html A new way to Hand feed-With a Cup...
forums.avianavenue.com
I see some budgies in your profile photo. Are all of these birds in separate rooms? They should be nowhere near this new bir until it is old enough to go to the vet and be tested for diseases. In the meantime, strict handwashing and clothes changing protocol between handling the birds.