The following items are things to consider if you are planning on taking a semester off to work full-time in a career related field/position. Please note: It is your responsibility to take the necessary steps prior to leaving campus, to arrange a work absence from the University.
Steps to consider: 
If you have a scholarship or are receiving Financial Aid, be sure to check with those
offices to determine the impact that this could have on your award.
Determine if your academic standing allows you to take a semester off to work full-time.
Check the University of Arizona policy.
Plan your work semester in advance and think ahead for the next semester.
Things to consider: your classes, housing, finances, travel time/expenses, and others.
Other options that you should consider:
If you are interested in securing academic credit, see your academic department to determine what their academic credit policy is and the cost involved.
If credit is not an available from your academic department, consider other options such as credit from course LASC 393/493 from the CLAS Academic Advising Center.
If you are considering taking classes while out working, ask your academic advisor which classes will transfer back to the UofA.
If you are interested in maintaining your full-time status, consider registering for Co-op 100.