You can take surprisingly good naps sitting in a toilet cubicle - I did so for many months at Accenture and never had a problem. It energised me and enabled me to do better work the rest of the time.
I thought I was the only one weird enough person in the world to actually nap in a toilet. I can say a lot of good things about my company work culture, but unfortunately, naps in the middle of the work day are frowned upon there.