The victims were aged between 20 and 30 years old and were transported to Faro Hospital.
According to newspaper Correio da Manhã, the family had decided to burn firewood in the house to warm up, causing them to become intoxicated with the smoke.
The incident happened last Tuesday; the alarm was raised at around 5:45 pm and was attended by firefighters from Tavira, Olhão, the Red Cross, INEM and GNR.