I will speak out of my experience with working at night. AFTER I STARTED WORKING in a call center , i had to work anti-clockwise , as the company was US based while we are in the Philippines. .
first problem for me, was the obvious, fighting not to sleep at work, there are days no amount of coffee would do, my body just needed to rest. This was also as a result of another problem.
lack of proper rest. since i had to sleep during the day where everybody else is busy, i found my self lacking the ample rest i needed. there was noise interruptions from people in the house and the school near by. there are times i personally had to run errands during the day, therefore my sleep would be sacrificed. i used to go to work on zombie mode.
this in the long run resulted to me being very moody and very irritable, at some point i felt that my body was giving up on me, fatigue kicked in, viral infections such as flue and i haven't felt worse, as the time i worked in a call center, It reached a point where i just had to FIRE my boss because my health and well being was more important that the amount offered.