Can EM Physicians work extra shifts for extra compensation?

Okay, I know I'm just a naive pre-med -- but I was wondering if EM docs can take on extra shifts for extra pay.
I figure if investment bankers and corporate lawyers can work crazy hours, physicians can too.

I've heard that EM docs work three 12-hour shifts a week. What if I were to do five, and survive by drinking coffee and energy drinks? I would only do this for like a year or two to erase my loans and buy a car.

To ER docs: I've never done a single shift so I don't know how hard you...

Can EM Physicians work extra shifts for extra compensation?

Can EM Physicians work extra shifts for extra compensation?