Chopped bacon was added for that authentic touch when it came to depicting someone's spilled brains. But the freezing Antarctic snow and winds were entirely natural.
South Of Sanity, billed as the first-ever fictional feature film to be shot in Antarctica, is a wintry slasher/horror film that will premiere in Aviemore and New York at the end of this month.
The 90-minute-long film uses "actors" who were, in reality, all colleagues at a remote British Antarctic Survey (BAS) base. It follows the bloody misfortunes of 14 people trapped on a station for nine months. Eventually, after all contact is lost, a rescue team investigates. No-one is found alive but a diary reveals they had deliberately been picked off one by one.
The film has secured an 18 rating from the British Board of Film Classification with the warning: "Contains strong gory violence."
Kirk Watson, 36, who is based in Aviemore and is an experienced cameraman and qualified mountain instructor, shot, edited and, with Dr Matt Edwards, co-directed the film.
Watson said that when he signed up to join the BAS, he was advised to consider taking up a project for the long winters.
"In the summer you don't have any spare time, you work very long days helping with the science as the daylight lasts for 24 hours. But it becomes dark in winter, the staff numbers drop – there were only 21 of us in the station in the winter – and once you finish work you have lots of free time. You don't have to commute home, go to the shops, mow the lawn, and there isn't much of a social life.
"To fill in their free time some people learn the guitar or other musical instruments, or get into photography or learn a language. I learned to make films in my free time over almost six years in Antarctica and that culminated in my last winter, where I decided to move it on a bit."
Matt Edwards was writing a script. It began as a short horror story but he and Watson decided to make a feature film together. "He wrote it and I filmed it, and it turned out to be a really good project. It filled in a lot of spare time for everyone there.
"We didn't have actors as such but the fact that they knew each other so well meant they could act out in front of others and not get embarrassed. They were also extremely used to me having my camera with me all the time, so they just did their best.
"We got some pretty good results, but if they weren't good at acting we just killed them off pretty quickly. I was one of those who were bumped off quickly – acting isn't one of my strong suits."
The budget for South Of Sanity was virtually non-existent. Because there was only one camera, scenes could only be filmed from one angle at a time.
Dr Edwards, whose mother is a make-up artist, relied on a child's face-painting set from Mothercare and various kitchen items. Station mechanics helped make some special effects from old metal recovered from a skip. Watson said: "We had someone moving around with an ice axe sticking out of him so we had to make metal plates to wear under their jumpers then bolt the ice axe onto it so it was rigid on them.
"We're pretty happy with the film but as film-makers you always look back at projects. Matt and I watched it a fortnight ago and wished we could have changed certain bits.
"But some friends who have seen it have said it is much better than some horror films they've seen."
After the Aviemore premiere on October 31, the film will be available from Watson's website and elsewhere. A US distributor is advertising the film across America.
Watson is currently working on a documentary about Scots climber and mountaineer Dr Tom Patey, who died in 1970. The duo behind South Of Sanity have also been asked to join a team that will fly microlights to the South Pole next year in a bid to break three world records, with Watson filming it and Edwards acting as the team doctor.