Summarize this article:

Give the fries time to cool before frying a second time. For a quick turnaround, put them on a pan in a single layer inside the freezer. Otherwise, allow them to rest in the fridge overnight in a paper-towel lined sheet. No matter the method, allow the fries to come back to room temperature before the second frying. This allows even cooking.

Summary:
Allow the fries to rest.