A MOTHER-of-two has set her sights on becoming the first Scot to complete a trio of gruelling marathons in Antarctica, taking on temperatures of -40c and the threat of polar bears.

Audrey McIntosh, from Glasgow, has already completed two of the extreme events and is aiming to finish the third, the North Pole Marathon, also known as the World's Coolest Marathon, on April 9.

The 51-year-old is competing in the events in aid of Alzheimer Scotland and has already raised £15,000 for the charity. She hopes to eventually raise £20,000 in total.

Ms McIntosh said: "This will be a tough challenge physically and mentally, but I am prepared and motivated to succeed by my fundraising."

The runner has already completed the Antarctic Ice Marathon and 100km Antarctic Ultra Marathon, but the final one will be her toughest to date as she will be running on frozen sea, which has been compared to running on wet sand. She will be accompanied by armed marksmen to protect her from polar bears.

Ms McIntosh also plans to compete in a 53-mile Ultra Marathon, The Hoka Highland Fling, in Glasgow just two weeks after her North Pole race.

Anyone looking to donate to her fundraising efforts should visit www.justgiving.com/Audrey-McIntosh1.