100 miles of ice-cold courage.
Mr Archer, 53, of Ingleby Way, Blyth, Northumberland, is training for the Yukon Arctic Ultra in Canada, billed as the world's coldest and toughest ultra-marathon.
He will try to pull a sled loaded with equipment through 100 miles of spectacular frozen scenery in just three days, braving snowstorms and extreme cold.
Competitors on the trek ( from the Yukon capital Whitehorse to Braeburn ( will face temperatures of -40C, freezing winds and threat of frostbite and hypothermia.
The postman, who completed a 150-mile ultra-marathon across the Sahara Desert four years ago, is getting himself in shape by dragging car tyres along Blyth beach to build up his strength.
He is seeking sponsorship for the Yukon challenge to raise money for the Blyth Volunteer Lifeboat Service (BVLS), which ran the successful campaign to run an all-weather lifeboat.
The trek, from February 11 to 24, offers routes of 100 miles on foot, 300 on skis or 460 on foot, mountain bike along the Yukon Quest dog sled trail.
Mr Archer said: "I take part in these challenges for fun knowing what I face, but the lifeboat crews go out not knowing what they face and putting their lives at risk to save others."
Sponsor Ian by emailing the BVLS at firstname.lastname@example.org