How To Defrost Leftovers From Freezer. How to defrost frozen cooked turkey. Make sure they’re thoroughly defrosted before heating, by leaving them in the fridge or using a microwave.

Frozen and thawed food will develop harmful bacteria faster than fresh. It is safe to reheat partially defrosted leftovers using a saucepan, microwave or oven. So, defrosting at the countertop is not a smart move.