My Son (3.5 Years) Has Been Showing Slight Rectal Prolapse

my son (3.5 years) has been showing slight rectal prolapse since 2-3 months. recently the prolapse is getting severe with bleeding, straining during defecation and tenesmus. its been more than a year since he was dewormed. he has fever since yesterday night. still has fever. can i deworm him now, when he is having high temperature?