Export a Video Overnight

I'm exporting a one hour long video and the exporting process will take four hours (according to the estimation). It's evening now and I already need to sleep. I thought of leaving the exporting process on going overnight but my laptop constantly goes to sleep so I have to manually wake it everytime or else, for some reason, it will turn off. Thus, I'm required to remain awake (but I can't, I really can't). What should I do before leaving my laptop in exporting process overnight without my sleep getting interrupted?