Hi Katrina, I would call your manager and speak to them right away! Also getting a doctor's note wouldn't hurt if the sun burn is really bad to the point where you can't work or wear a shirt I would go anyway to get some medical cream to speed up the healing process. I hope you feel better soon! Make sure to give them a call and tell them when you will be ready to return to work and that you are so sorry for missing a few days!