No. Overnight oats are not cooked with heat but instead they are prepared using a cold method instead of the traditional stovetop cooking or microwaving. Overnight oats are made by combining rolled oats with a liquid, such as milk or yogurt, along with other desired ingredients, and then letting the mixture sit in the refrigerator overnight (or for several hours) to soften and absorb the liquid. During the overnight soaking process, the oats absorb the moisture from the liquid, resulting in a softened and creamy texture. This gives the oats a cooked-like consistency without the need for heat. The oats become more tender and easier to eat compared to eating them raw.