Much of France was hit by snow and freezing temperatures in late November. Migrants living on the streets, due to a saturated emergency housing system, are doing their best to survive outside. "Winter is always the hardest season; the one that worries us the most for migrants and homeless people," said Francesca Morassut, coordinator for the Parisian branch of Utopia 56.

The branch typically counts, "between 150 and 200 people, including women, men, and between 50 and 60 children, every evening in front of the Paris City Hall," said Yann Manzi, co-founder of the association.

One recent November evening, "141 people showed up, with 53 children, and 13 children under the age of three among them," said Morassut. Utopia 56 tries to accommodate these people with shelter, especially in a warehouse with a capacity of up to 130 people," added the coordinator. "Yet it’s not enough, dozens of families still spend the night outside in the cold, or in train stations, hospitals or under bridges."

Read AlsoFrom amputated digits to death: The effects of cold on migrants crossing Europe's borders

Then there are the other cases: for those "abandoned by the 115" [an emergency number to call for those with no accommodation], associations provide them with tents, sleeping bags and blankets to help them stay warm at night. "This is strictly emergency equipment, it exists in limited quantities, and it is not at all adapted for the current weather conditions, like snow, rain, or bad weather," said Manzi.

"In one camp inhabited by older men, I saw some people wearing flip-flops, who didn't even have closed shoes. They also often don't have warm coats, gloves or hats, so we try to bring these items with us when we roam the streets [looking for homeless migrants]," said Morassut.

Forced to stay awake at night

Whether it’s during the day or at night, the cold is unforgiving. "The nights are extremely short because the migrants constantly stay awake in the biting cold. At dawn, they look for somewhere to warm up," said Milou Borsotti, project manager at Médecins du Monde (MdM). "They have to walk at night, rather than sleep, to try to avoid freezing to death," said Manzi.

Besides the cold, the humidity and the constant risk of being evicted by the police also contribute to the migrants' misery. "The post-Olympic policy of making migrants invisible is still in place," said Borsotti. "They cannot keep their place of residence during the day without being chased away by the police. The 150 unaccompanied minors living at Pont-Marie must fold and hide all their belongings, their sheets and their blankets as early as 7 am. Since it’s outside, they have lately been finding their belongings completely soaked by the end of the day," said Borsotti.

The cold weather represents a serious risk to the health of those without housing, with hypothermia being a major danger, say non-governmental organizations (NGOs). "Surviving outside in winter means exposing yourself to many cold-related illnesses: colds, headaches, frostbite, musculoskeletal pains. There is also the exhaustion which is reinforced by the cold," said the project manager.

Being exposed to the cold also has an impact on migrants’ mental health. "In these weather conditions, we see even more distress and despair among the homeless migrants. They simply need a warm place to rest," said Morassut. As for the camp of 150 minors established in the center of Paris, "they feel abandoned and ignored. They worry about being left outside, in the cold, for an indefinite period," said Borsotti.

Read Also'Winter is starting': NGO warning as migrants suffer frostbite at Poland-Belarus border

'Their tents are full of water as soon as it rains'

These concerns exist well beyond the capital. Some 200 people were camping in the northern-western city of Rennes on November 21, despite the snow and temperatures of around three degrees Celsius, according to Manzi. A petition was launched Thursday to call on politicians to provide migrant families currently living outside with decent accommodation for the winter.

"The young people are in tents that are full of water as soon as it rains, they cannot sleep or concentrate on their lessons at school. Preserving food, cooking, even the most basic hygiene gestures are becoming nearly impossible in the current conditions," claimed the petition.

The same day, the prefecture and the city of Rennes indicated they would make a gymnasium available until Monday to respond to the cold spell. The space could accommodate around twenty people, according to the local media Rennes Infos Autrement.

Manzi estimates that in the North some "1,000 to 2,000 migrants are abandoned from Calais to Dunkirk." The prefecture refused to trigger the contingency plan for extreme weather conditions (for homeless people) since the temperatures above zero degrees Celsius didn’t meet the plan’s activation criteria.

Read AlsoMigrants 'living in swamps' after storms hit northern France

Aid groups call for urgent action

Faced with this "dramatic situation", Utopia 56 reported sending letters to the Île-de-France prefecture, the Regional and Interdepartmental Directorate for Accommodation and Housing (DRILH) and the Paris City Hall to ask them to free up spaces to temporarily accommodate vulnerable and marginalized populations. "There are many empty offices, high schools, gymnasiums and closed buildings in the capital that could be used", said Manzi.

Only the city hall responded, reporting that it had contacted the DRILH and prefecture, and opened a few facilities without being able to do much more. The Paris City Hall said reinforcements and opening of other emergency accommodations depended on weather alert levels and the prefecture. "The alert level of the past few days was not high enough and didn’t last long enough to trigger an extreme weather contingency," it said.

"There are still some isolated operations to provide shelter carried out by the prefecture. For example, a group of 150 people camping along metro line 2 in Paris on November 20 were sheltered in centers in the Paris region," said Milou Borsotti. "Yet we remain dismayed by the lack of action from the public authorities with the growing number of homeless people and families evicted from empty buildings, and winter is approaching."

Read AlsoParis: Police 'evacuate' 400 young migrants without offering alternative shelter