Judicial Magistrate First Class Kshama Joshi rejected the application by Tejpal, who has been lodged in Panaji police custody since Saturday in connection with a sexual assault case.
On December 2, Tejpal's lawyer had argued in the court that a fan be allowed to be put up in the lock-up on humanitarian grounds.
The 50-year-old Tehelka founder was taken for a second round of medical tests in Panaji, Goa.
His medical examination was earlier conducted on December 2 at Goa Medical College and Hospital, where various tests, including potency examination, was conducted on him.
Tejpal was arrested last Saturday after his anticipatory bail plea was rejected.
He was remanded in six days police custody on Sunday.
Tejpal is accused of sexually assaulting a woman journalist in a lift during a Tehelka event in Goa.ht