To Cram or Not to Cram...
There May Be No Question!
It is never a good idea to learn a lot of material in a short time period, but sometimes that is the predicament you've put yourself in. Giving up not being an option, there are some techniques to follow when trying to learn a large amount of material in an impractical amount of time.
When your time is limited, whether to a night or a few days, you have to choose what to study. Focus on the main ideas and formulas that you believe will get you the most points on the exam. To maximize your available time read chapter summaries or skim text to narrow down key concepts. Study from past tests, quizzes, homework and review information. If your own notes are incomplete (for whatever reason) try to study with someone who has a better version or ask if you may copy theirs.
Study in a quiet area, but make sure it isn't too comfortable because comfort encourages sleep. Take short breaks every hour. A stretch, shower, or short walk can help you re-energize. Try to sleep in 3 hour increments; they are the sleep cycles proven to be most beneficial. Sleep will aid in concentration when you are actually taking your exam. Remember to set your alarm and ask a roommate or friend to make sure you wake up. Most importantly, next time manage your time effectively to keep yourself out of the situation of having to cram for any exam.