Out in the open in freezing weather, Mustafa Hamadi and his family settled into their makeshift tent in the village of Killi, in the northwestern Syrian province of Idlib - their second displacement in less than a year. The sub-zero temperatures on the night of February 11 kept them awake so, just before midnight, Mustafa moved the gas heater inside the tent.
By morning, Mustafa, his wife Amoun, their 12-year-old daughter Huda and their granddaughter Hoor, who was just three years old, were all found dead of carbon monoxide poisoning.
According to Nizar Hamadi, Mustafa's brother who was texting with him that night, the tent - constructed of metal pipes and nylon sheets - had no proper ventilation and did little to insulate Mustafa's family from the cold.
"It must have been minus nine degrees Celsius (15.8 Fahrenheit) that night," Nizar told Al Jazeera. "My brother knew better than to bring a gas heater into an enclosed space with no air vents, but what choice did he have?"
The Hamadi family, originally from Kafrouma village in the Maarat al-Numan countryside, were forced to leave their homes last summer and move further north amid an intensifying Syrian government aerial bombardment on Idlib, the last major opposition stronghold in the country.
Mustafa and Nizar settled in an empty unfinished school in the town of Binnish, some 8km (five miles) east of Idlib city, before Mustafa moved to Killi as the shelling escalated.
"The school is not fit for living," Nizar said. "But there is not a single house that has not been occupied by previous rounds of displaced people. Some rooms have three of four families living in them. The people displaced are like a snowball on the move, getting bigger every day."
Families sleeping without shelter
Backed by Russian air power, Bashar al-Assad's troops in April last year launched a major offensive in Idlib, home to more than a million people, the majority of whom were transferred there en masse from other areas captured by government forces. The military push disrupted a fragile cooperation between Turkey and Russia - backing opposite sides in Syria's conflict - that had designated Idlib as a de-escalation zone.
The campaign continued as several ceasefires failed to hold up. In December, the Syrian government intensified its assault on the region in a bid to seize the strategic M5 highway, which runs through Aleppo and Idlib provinces and was once a major commercial route.
The offensive, which has also forced residents of western Aleppo to flee to Idlib, has killed hundreds of civilians and caused the largest single displacement of people since the war began in 2011, with at least 900,000 people forced to flee since December, according to the United Nations.