It's best to use this method if you're going to cook the food, or for frozen fruits and berries that you're going to serve immediately. • 4. At room temperature: Pastries, breads, and fruits may be thawed for 2-4 hours at room temperature. Do not use this method for meat, fish, and vegetables. • 5. Under running water: Meat may be thawed under cool running water. See Kitchen Shortcut: How to Thaw Meat Quickly.