Thank you for asking Healthcare majic. My name is Dr Ehsan Ullah & I have gone through your query. There are several Causes for balls redness which include Blunt injury infection and some allergic skin conditions well, your question was to know whether these are due to fever.... Fever can be because of such redness of the balls and these need clinical evaluation by the nearby Physician to establish diagnosis and to check whether it s just redness or there is some swelling etc and proceed accordingly with treatment. Hope this may help you. Let me know if anything not clear. Thanks.