In the following lines:

In the lines you provided, the words that create alliteration are:

• "real" and "relax" from "real chill"
• "fall" and "fitted" from "fall crisp" and "fitted with my need"
• "need" and "no" from "no warm house"

Alliteration is the repetition of initial consonant sounds in closely placed words. In your lines, "real" and "relax," and slightly less pronounced pairs like "fall" and "fitted," contribute to the overall rhythm and sound of the poem.