Almost 2,000 people in Cornwall will be homeless this Christmas, new estimates suggest.
It said the "housing emergency is out of control", and called on the Government to take the issue seriously.
The figures show 1,900 people are estimated to be homeless in Cornwall this year.
Of these, 1,876 live in temporary accommodation – organised by social services, the council or themselves – including 895 children.
Meanwhile, 24 of the total homeless population are sleeping rough.
Nationally, around 309,000 people will be without a home this Christmas.
Homeless figures are snapshots or estimates of the problem, and they often undercount the true number.
Polly Neate, chief executive of Shelter, said: "Homelessness is on nobody’s Christmas list, but 309,000 people will spend this time of year in a tiny hostel room or freezing in a doorway."
Ms Neate blamed the housing emergency on "chronic underinvestment" in social homes, with people unable to afford rising rents.
"It is appalling that the Government has allowed thousands of families to be packed into damp and dirty B&Bs and hostel rooms, which are traumatising children and making people desperately ill," she added.
"Until the Government takes this emergency seriously, our frontline services will do everything they can to help people keep or find a safe home this winter.
"It is only with the public’s support we can continue to provide vital advice and support and fight for the solutions people want and need to end homelessness."
In England, one in 182 people are homeless.
This is compared to one in 300 in Cornwall.
The Department for Levelling Up, Housing and Communities said it is spending £2 billion on tackling homelessness and rough sleeping.
A DLUHC spokesperson said temporary accommodation is "an important way of making sure no family is without a roof over their head", but councils must ensure it is temporary and suitable for families' needs.
Funding to address homelessness includes £1 billion given to councils to financially support people moving out of temporary accommodation.
"Through our Rough Sleeping Strategy, we will continue to work to end rough sleeping completely," a spokesperson added.