Just take it out the night before packing and put into the fridge to thaw. When you are ready to pack lunch throw it in the lunchbox. My kids have a microwave they can use for reheating but you could put it piping hot into a Thermos also. I had ten containers so I popped two in the fridge. One for the boy for lunch tomorrow and one for my mom to reheat for dinner. This is so much better for you than canned beefaroni . I am sure glad you stopped by and I hope to see you soon. Have a great day!