Personally, overnight cram sessions have never been very helpful to me. It might work for some people, but I find that I tend to forget it all really quickly. This isn't necessarily the best thing since courses further on require you to have an understanding of their prerequisite courses.

Time management is the key to avoiding this. As finals near, it's a smart idea to have a calendar that contains time segments (almost like an appointment book). This really helps me organize my time for studying. It's also important to realistically plan your time. If you have a somewhat short attention span like I do, studying for four finals in one day with minimal breaks isn't very efficient. Over scheduling can affect your mood. If your list is too long and you find that you didn't complete it all by the end of day, you feel like you've wasted your time and get more stressed.

Stress, with the combination of all those take out food you've been eating, can be detrimental to your health. It can also affect your studying. Remember to take breaks and plan your time wisely during finals week. It will be beneficial for you in the long run and with your exams.