What should you do when you get tired with a long day ahead of you?

This has happened to me many times before! What you should NOT do is drink a energy drink they make you awake but soon as they wear off you are even more tired than before! So what you should do is try to take a small cat nap! But if you cant do that... just try to make it until to you get home! But if you really cant even concentrate on what you are doing then you should just stop and go home so you can go to bed! Because it is bad to strain yourself!