In The Trenches: This Foot Injury is More Common than Backpackers Expect

Each morning, I braced myself and pulled on cold, wet double socks, laced up damp trail runners, and continued hiking Canada's Great Divide Trail northbound, through sodden brush, icy river fords and muddy bog.

Each evening, I wrung out the socks, cleaned my feet, and sheathed them in dry socks, sometimes with a handwarmer in my sleeping bag toe box. My footcare tactics kept the skin happy: no maceration, sores or gangrene. And I reached the finish line proudly thinking I had avoided trench foot.

I was wrong. Because I didn't understand what trench foot is.

Beyond skin symptoms, trench foot is a nerve and circulatory issue, caused by sustained immersion and cold. The NOLS Wilderness Medicine handbook warns of "subtle forms of nonfreezing cold injury," which may not manifest with skin discoloration, let alone gruesome stereotypes of foot rot.

My symptoms showed up post-trail, with swelling and numbness lasting 3 to 4 weeks. I wasn't alone: Resupply and shuttle coordinator Sean Prockter estimates that half of this year's GDT thru-hikers suffered some level of trench foot.

"Many of us got secondary infections to trench foot," confirmed thru-hiker Meghan Dwyre. "I heard of a couple helicopter evacuations, and others who barely hobbled out." Kakwa park host Kim Jollymore and thru-hiker Carlie Gale corroborated reports of a male hiker airlifted off trail with severe symptoms.

While the GDT was unusually wet and cold in 2025, this is a common issue. Filmmakers Ryan Brown and Ilse Praet also experienced what Brown describes as a "combination of trench foot and athlete's foot" on their 2022 hike.

Occasionally, hikers may have a choice to bypass braided rivers entailing extended immersion in icy water. In other places, there may be no dry-feet options. Hikers in the trenches would be well-advised to carry dry socks for the night, consider options like waterproof socks or hydrophobic foot balm during the days, and be aware that trench foot may be a subtler injury than expected, with the potential for lasting consequences.

— Caitlin Hardee