Los Angeles, Jan 15 (IANS): Actress Jodie Comer spent hours in freezing water and mired in studies on pregnancy for her latest tough role.

The actress portrays a terrified new mum called only "Mother" in the upcoming apocalyptic climate change drama 'The End We Start From', who is desperately trying to keep her baby Zeb safe when she is forced to flee her London home amid disastrous flooding.

Its director Mahalia Belo said Comer, who doesn't have any children, was happy to embrace the gruelling shoot, which involved braving sub-zero waters near Lochgilphead, in Argyll and Bute, reports aceshowbiz.com.

The filmmaker was quoted by the Sunday Mirror as saying: "It was freezing. We spoke to Jodie and she wanted to do it."

"She's a believer in truth and felt this is what the character would do. It was so beautiful and she just went for it," the director additionally gushed over the actress.

"We felt like such renegades, Jodie naked going into the water."

Jodie shot the film for 30 days between her stage drama 'Prima Facie', in which she played a lawyer who gets raped by a colleague, moving from London to Broadway.

Mahalia added about how Jodie spent hours getting prosthetic baby bellies fitted for her role as Mother: "We wanted to tell the woman's story from pregnancy to that first year as truthfully as we could. (Jodie wanted) to serve it properly. It looked so real! We also had make-up do stretch marks and prosthetics made a few weeks-after belly."

Jodie has told Channel 4 about the lengths to which she went to make the movie, "Not being a mother, it was about getting to the bottom of the way you hold your body when you have a baby, the way you feel the pain, the stages of labor... to make that feel as real as possible."