The series is fiction, and has multiple books. The cover I had of the third book has fire and an animal along with the protagonist, I think. The protagonist is a person so it cancels out any books with animal protags. (Mammoth Trilogy, etc..)
The first book's cover is impossible to remember, but there was probably a scene involving winter, ice and maybe a river? Someone saves the protag.
The protagonist leaves his home, along with leaving the tribe that cared for him. Along the way, he seems to fall into an icy river? Another human saves him? The characters use "summers" instead of years, and the MCs are most likely teenagers.
I last read this book somewhere around 2017-2019, and can't remember any names at all. Winter is a conflict in the first book (freezing to death is bad apparently), so it's set around the ice age.
It was probably made after 2000, perhaps after 2010. If I were to give it an age rating, it would probably be PG? On-par with Wings of Fire and Warriors.