Honest Opinions

So I have a career dilemma I guess you could say. I'm in school full time and working a retail job part time. Hate retail but it's money for right now. I just found out about an opportunity in my field of study that is part time but offers pay and experience for my resume. However, over the summer, I will be out of state working an internship. Would it be wise of me to take the job for rn and then ask for the summer off or is that unprofessional and rude? btw, the internship isn't in my field but is a great opportunity that I can't pass up. What should I do?