Overnight oats are typically eaten cold, after being soaked in milk for several hours. They are an ideal make-ahead breakfast that you can prepare the night before, and grab on your way out the door in the morning. You can heat up your oats in the microwave if you would prefer them warm. Just add a little more milk to your oats, then heat in short bursts in the microwave for a total of 2 minutes, checking and adjusting the consistency as you go.