My Daughter Had An Emergency Appendectomy For A Perforated Appendix

My daughter had an emergency appendectomy for a perforated appendix four days ago. She has not had a fever since her surgery. She does not have a fever now, but she is sweating tonight and complained of being chilled earlier. Do I need to take her back to the hospital? Her pain has been managed by two doses of tylenol and one dose of ibuprophin.