The lives of thousands of Iraqis fleeing Islamic State are at risk as temperatures drop to zero near Mosul.

More than 77,000 people have been displaced from the region surrounding the city since the offensive to retake Mosul from ISIS began on October 17, the UN has said.

As winter approaches, Christian relief and development agency Tearfund has launched emergency measures to help support those at risk of the freezing temperatures.

"Thousands of people are arriving in camps everyday with just the clothes they are standing up in, and few or no possessions, having had to flee for their lives as the assault on Mosul continues," the organisation said on Friday.

Tearfund has therefore begun distributing winter clothing to people living in the Qarmawa IDP Camp in Ninewa.

One recipient is 60-year-old Ryad, who with his family was forced to hide in their home for more than 24 hours when the offensive began.

When they decided to flee, they had to leave everything behind and arrived at the camp with just the clothes on their back.

"They killed one of my relatives. When we tried to run away my son was shot two times in the stomach and my granddaughter in the leg," Ryad told researchers.

"I have many more relatives who are still in Mosul, we do not know what has happened to them.''

"In the last week the temperature in the camps has dropped to zero or -1 degree at night, yet thousands of people are arriving just in T-shirts, having left everything behind," said Betsy Baldwin, Tearfund's Iraq response manager.

"For the past few months we have been working to pre-position vital supplies, including cooking stoves, blankets and mattresses and have now started distributing clothes to over 5,000 people, to keep them warm as the long winter sets in. More distributions are planned as the cold weather continues."

Anna Chilvers, Tearfund's emergency programme manager, said the organisation is using a voucher system to help civilians purchase the winter clothes.

"It gives people an element of choice – they can choose the sizes, colours, styles, whatever suits them," she explained.

"We want people to feel valued and create a shopping experience – something normal after living in a place whether people's lives are treated as worthless. It's not just about the numbers, it's about caring for people. I'm so glad when I see a child walk in with no shoes, and walk out wearing a brand new pair."

Ryad, meanwhile, remains hopeful that his family will one day enjoy a normal life beyond the camp.

"My wish, my hope, is that we return back to our homes, to restart our life there," he said.

Tearfund is not accepting clothes donations as all clothes will be sourced from a local supplier, but donations to its Iraq appeal are welcomed.