That's why I keep 3 alarm clock with me
. One actual alarm clock, another is my cell phone, and finally, the last option, my laptop with a program that play a mp3 file at the loudest volume.
The reason is, I never trust myself to wake up... The "oh I will just lay down for 10 more seconds" always gets me at the worst times.
Falling asleep by the scoring table, on the other hand, will make sure I wakes up.