Your shirt catches fire while leaning over a bunsen burner what should you do?

If you're in a laboratory and your shirt catches on fire when using a bunsen burner, the first thing you should do is stop, drop, and roll. Stop, drop, and roll is a technique to put out a fire.

First, stop whatever you are you doing. Next, no matter where you are, drop to the ground as fast as possible. Lastly, role on the ground repeatedly until the fire is put out.

If there is a fire blanket around, have someone get the blanket and they will put it over you so it will be put out.  

answer; no longer than a reasonable period of time;