system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why is it bad to cook chicken from frozen even when it cooks high enough to kill bacteria?
gpt
Cooking chicken from frozen is perfectly safe, **as long as it's heated to a safe temperature (165 F) all the way through to the middle**.

The difficulty is that if it's frozen, it takes so long for the *center* to cook through that the *outside* ends up overcooked and dry.

This problem can be solved by creating a cooking environment that stays not too far above 165F for as long as it takes (which could be hours).  This means using a crockpot ("low" for most of them is around 200F), or poaching (as long as you hold the poaching liquid around 180-200F and keep topping it up), or using a sous vide setup.