When you're under pressure and someone treats you like dirt at work, how do you deal w/it?

I'm a phlebotomist (I draw blood for lab work), and am a new hire at a hospital. I'm finding many of the staff, primarily nurses, tend to treat lab people like janitors. I was yelled at in front of a patient's family members by a nurse and was shocked at how unprofessional and completely inappropriate this outburts was. Any suggestions how to keep my cool, stay under the radar and perform my job without getting involved in this B.S.?