Severe snow and sub-zero temperatures have wreaked havoc across the UK, but present a dire threat to those living without shelter. With weather predicted to worsen, churches and homelessness groups across the country are opening their doors to help those in need, and have condemned the 'injustice' of the rough sleeping crisis.

Jacob Quagliozzi, the director for England of Christian charity Housing Justice, tells Christian Today many experiencing homelessness are now in an 'exceptionally dangerous' position.

'Across the country Christian groups and churches are working with other faith groups and local communities to provide shelter to people experiencing homelessness throughout the winter and particularly during this period of sub-zero conditions,' he says.

There are now more than 107 night shelters in the Housing Justice Church and Community Night shelter network, Quagliozzi says, adding: 'We estimate this will see somewhere in the region of 6,000 people accommodated throughout this winter.'

But, he says: 'With a number of tragic deaths on the street this year we as a society must act to address the root causes of homelessness so that people are not left without a permanent home in the fifth richest nation on earth.'

John Kuhrt, chief executive of West London Mission (WLM), tells Christian Today that 'Christian groups are at the forefront of responding' to the current conditions, but 'the crisis is that there are far more people on the streets than there are rooms and beds available'.

WLM is a Methodist-based charity that's been serving the homeless for the past 130 years. On a usual day, Kuhrt says the centre engages 80-100 rough sleepers, while a night shelter it coordinates, alongside 13 churches, a mosque and a synagogue, runs for eight months in the year. So far this winter, he says, the charity has helped 44 rough sleepers move into accommodation, while this week's severe conditions have prompted it to open up an additional 20 beds at its centre.

To tackle the need, he says, 'We have to ask hard questions about proper sustainable solutions rather than just an issue at Christmas and when it snows.'

He adds: 'Homelessness says something very challenging about how our society is broken and the effect that it has in marginalising people, and I think it's heartening to see people put their Christian faith into action to make a difference.'

Ahead of worsening weather conditions, WLM is speaking with Westminster council to provide 100 more beds for the homeless.

Some rough sleepers can be resistant to the shelter offered by charities. 'Helping people come off the streets can be very complicated. It's not as simple as 'they're choosing not to come in', Kuhrt says.

'People are very damaged and have a lot of mistrust, fear about coming indoors. But a lot of people who might be reluctant to engage are saying "We want to come inside because it's so freezing."'

The Connection at St Martin's, the busiest homelessness centre in London, wrote on its website: 'While rough sleeping is dangerous at any time of the year – the average age of death is just 47 years of age – when the weather becomes severe, and temperatures drop below zero, prolonged exposure to the cold increases the risk of death to people without a roof over their heads.'

The charity, like several others, is now operating under Severe Weather Emergency Protocol (SWEP), a local authority initiative which coordinates agencies in an effort to protect the vulnerable.

Pam Orchard, chief executive of The Connection, says: 'We are running SWEP at the moment with our partners. We work very hard together to get people off the streets at night when the temperature plummets. Our Street Outreach teams are going out daily to find people, and we significantly increase the capacity in our emergency night centre. We do everything we can to ensure very vulnerable people come out of the cold and into the support services they urgently need.'

Those concerned about at-risk homeless individuals can use StreetLink, an England and Wales referral service that can help deliver necessary services to rough sleepers. The Connection's day centre, like several emergency day and night shelters across the country, is offering vital respite from the freezing outside conditions, including hot food, extra warm clothing, a hot shower and NHS support.

Neil, a street outreach worker for The Connection, says: 'When the weather's bad people are at more risk of chest infections and in severe cases hypothermia. We do what we can to get people to take up offers of help, but not everyone is willing to, because of poor mental health for example, and in these situations, it's very difficult because we can't force people to accept help.'

The Met Office has issued red warnings – its most severe weather alert – for snow affecting South West England and Wales, just the second such warning it has issued for snow since 2011. Heavy snow and freezing temperatures are expected to worsen across the country in the next 48 hours, leaving the UK's travel and power infrastructures at serious risk. Today, thousands of schools have been closed and hundreds of flights grounded across the country.

For those who are homeless, there is usually somewhere to go – and often, it's a place provided by a Christian charity. But as West London Mission's John Kurht says, in the end, charity is not enough – what homeless people need is justice.

'The inequality and unaffordability of our housing situation is the worst injustice that there is in the country at the moment,' he says. 'It makes thousands of people vulnerable. As well as helping people, we urgently need to address the situation creating this poverty. As well as a practical concern, we need a political concern.'