A 52-year-old man is found dead in his locked apartment in Delhi during summer (ambient temperature 38°C). Police discover him on the floor of his bedroom. On external examination, the body shows greenish discoloration over the right lower abdomen with visible venous marbling on the chest and neck. The skin over the abdomen is blistered and peeling. Rigor mortis is present in all major joints. Based on these post-mortem changes, approximately how long has the body been in this state?