How to avoid fall into sleep while at work?

I usually sleep around 9:00-10:00 pm and wake up at 5:00-5:30am I guess I am an early starter, I used to wake up at around 7 am, felt tired but now I have woken earlier, I started to feel more energetic also doing some exercise helps alot.

You can take a bathroom break that's what I did when I was employed. I always got drowsy around noon.

Two years ago, I was working for two companies. I had a day shift job and a night shift job, working 16 hours a day. I got to sleep only four and half hours a day. Then, I faced the problem of feeling sleepy in the day shift office. Let me write down the tips. 1. Have something hot (coffee or tea) whenever you feel sleepy. 2. Talk to colleagues who are bot busy for some time. 3. Go to some intersting websites or read news for sometime. 4. Have a toffee or choclate for some time. 5. Have pepper or something hot(spicy)in your mouth for sometime. Hope this will be helpful to you. All the best.

if you feel sleepy while working freshens up by washing with water or stand for sometime and walk around don't stay in one place..

I drink water a lot, water which I do not like to drink everytime I have to do it when I am feeling sleepy at work and then I try to talk to many people so that I do not feel sleepy as I can sleep on my table or on my keyboard which I have done.

First sleep well so that you will not feel sleepy the following day, but if you cant avoid such you could definitely drink coffee( make sure it is really hot) but if this doesn't work try to make yourself busy so that you wont feel sleepy...