Hallow Mumma, I can understand your concern for your daughter. At menarche and even later for few cycles - may be some times for few years also, the girls do get varied symptoms during their menstruation. Most of the times these symptoms are associated with pain in lower abdomen. Such condition is called as Dysmenorrhoea. Even the menstruation is irregular for first few years. Slight rise in temperature may be noted, however, substantial fever is not a routine feature. She was already suffering from the cold; in that she went for swimming. This could has given her fever. The cold might be associated with viral infection which got exacerbated due to swimming. I do not think, this fever should be or may be attributed to the menstruation. Routine treatment for common cold might give her relief. So you may try Tylenol type medicines for her. Also get her blood counts done to see whether she has low haemoglobin and/or decreased immunity. Accordingly you may take further steps. Please observe her closely. If the symptoms recur during every cycle, you may get het investigated for thyroid function. Hypothyroid state is known in girls around menarche and adolescence due to growth spurt. In this state, the girls do feel shivering and cold. I feel, I have sufficiently discussed all the probable issues and related points with you. However, if you want to discuss with me any more issues, you may ask me direct question or contact me on nishikants@gmail.com.