A polo shirt will likely not work. Generally, you need to mount the camera lower than what a polo will allow. I use a button down shirt and mount the camera just about the sternum..... When I need to adjust the camera angle, I'll roll up a little bit of electrical tape and put it under the appropriate edge of the camera. If you do this with a polo, it will be hard to keep the camera hidden.
Hard work builds character and homework is good for your soul.