1. Rent a movie from the library. They have tons and tons of movies and if the one that you want isn't there, you can put in a request. I recommend this activity with ice cream or popcorn. Very relaxing.
2. Taking a scenic run or going to the gym. The chances are that even if you are completely bogged down by work, you have 40 minutes to exercise and not think about the world of academia. My ten-plus years of magazine reading has taught me that exercising produces endorphins, and endorphins make you happy (thanks Elle Woods).
3. Song break. Singing and dancing to one or two songs can be very inspirational. I recommend anything by Florence and the Machine, Mumford and Sons or Adele. Bonus points if you run around the room that you are in.
4. Hot chocolate with extra whipped cream from the Knight Stand. Tis' the season and the cold weather is an excuse to delight in this scrumptious beverage. Yum.
5. Watch a television show online. Do it,I know that you want to.
6. Take a nap. Really, I cannot emphasize how important it is to SLEEP when you are tired. If you don't it is all you can think about and you will wake up in a better mood. No one likes a crank, so catch a few zzz's please.
The moral of all of these tips is that resting and taking breaks are important and necessary to your mental well being. Relax! Or as my friend often says: "Keep calm and carry on."