Will they no longer let you sleep between shifts at work? When I worked 24 hour shift (the maximum the hospital would allow without a 4 hour break) I slept on a couch beside the ICU and one of the nurses would wake me up when my 4 hour nap was over.

Now that you are union are you paid OT or are you a salary employee? I used to be an OT hog for 3 weeks in the month and the last week I only worked 2 12-hour shifts and then had 5-7 days off. I think your 4 on, 4 off sounds pretty good too.