Oh I see:)
Some have had trouble uploading to BYC so they made a tutorial.
Read the article I linked you to, this is by a fellow BYC member who had a chick suffer frostbitten feet. She details what she did to treat him.
Here's how to upload photos
https://www.backyardchickens.com/threads/%E2%9D%85-posting-pictures-using-the-upload-a-file-button-%E2%9D%85.1212519/
You may also find the following article helpful. https://www.backyardchickens.com/articles/frostbitten-feet-the-adventures-of-scout.67277/
Can you post some photos?
How old is your chicken?
I would let her warm up slowly.
Here's some information
https://the-chicken-chick.com/frostbit-in-backyard-chickens-causes/
Where are the chickens housed?