Vinod, a resident of Arrah district in Bihar, had come to meet his friend Jaihind at Kosi Kalan area on Nandgaon road in Mathura district, police said.
The incident took place yesterday after Jaihind left the room for his night duty. Vinod lit coal fire in the to keep himself warm and retired to sleep after closing all the doors, they said.
Later, Jaihind broke open the door after returning from duty and found Vinod dead on bed.
According to police officials, the victim must have died of inhaling carbon monoxide which would have emanated from the coal fire.