Screen Name Required

A screen name is required for sharing content on REI. Click here to create a screen name before continuing.

Set screen name

My Story of Trenchfoot (and How You Can Avoid Getting It)

I once lost all the feeling in my toes for three months from “trenchfoot.” I was lucky, in the end, that I suffered no permanent damage.

How did this happen? Well, you might guess that I froze my toes off in pursuit of an extreme adventure—high-altitude mountaineering or dogsledding across the North Pole—but no. I was backpacking, in June, near my home in Wyoming.

Wind River Range vistaI started my five-day hike at a popular entry into the Wind River Range in sunny, warm, even hot conditions. In a matter of hours I gained enough elevation that I encountered winter snow that hadn’t yet melted off, so I ended up hiking through freezing puddles of water on the trail. My boots became saturated with cold, icy water, and I hiked on. On the second day it started to snow on me, and it grew much harder to take the time and effort to stay warm and dry.

At some point my feet got cold. Of course, I know when they got cold—it was when the icy water poured in over my boot tops. What I mean is, at some point they stayed cold and I didn’t do anything about it. And so my feet stayed cold for hours and hours, setting the stage for trenchfoot, more accurately known as “immersion foot” or a “nonfreezing cold injury.”

Trenchfoot skinAs I have since learned through the Wilderness Medicine Institute, the physiology is simple. In response to the moisture and temperature, my body acted to narrow the tiny blood vessels that fed my toes. This is a standard reaction to cold exposure called “vasoconstriction.” Smaller tubes meant less blood got through, so the other tissues in my feet, the skin, bones, nerves, muscles, did not get the oxygen that they needed to stay healthy. Nor did they get cleaned of the normal cellular waste they generated, which is supposed to be flushed away by the blood, filtered by the kidneys and eliminated in my urine. This waste built up.

The first tissue to be affected drastically was nerve tissue, which seemed to stop functioning. I perceived this as numbness that went away that evening when I warmed my feet, then came back the next day and persisted after the second cold day no matter how much I warmed my feet. In fact, the sensation of numbness in my toes persisted for about three months after I finished the trip.

Trenchfoot soresMy skin became red, itchy and painful when I warmed it, but that was about it. My feet returned to normal after three months, and I didn’t experience immersion foot at its worst: ulcers, infection of those ulcers, permanent nerve dysfunction, tissue death, amputation. All of these are possible.

You’d be better off not repeating my mistakes. The main rule is to never tolerate cold, wet feet. This starts with planning your activity and choosing appropriate footwear. Boots and shoes should fit well (and not squeeze the feet), insulate for the cold, and keep socks dry. Because any boot can become saturated if conditions are wet enough, consider using vapor barrier socks for your dampest slogs. Or, you can improvise these by using plastic bags to line your boots.

If your feet do get wet, take the time to dry them off, massage them warm again and change or at least wring out your wet socks. If you’re camping, sleep in a pair of dry socks that you keep at the bottom of your sleeping bag to guarantee that your feet get to stay warm and dry overnight at least.

Simple precautions and a little discipline will help you enjoy the wet conditions and not suffer from the cold.

John Hovey is an REI guest blogger and an instructor at the Wilderness Medicine Institute, a division of the National Outdoor Leadership School (NOLS).

Wind River Range and trenchfoot photos courtesy of John Hovey.


Posted on at 4:21 PM

Tagged: Hiking, NOLS, WMI, Wilderness Medicine Institute, footwear, immersion foot, trenchfoot and vapor barrier socks

Ratings and Comments

(0) (0)
write a comment
You already voted on this.
Log in to comment or rate.
A.T. Hiker Staff Member

I always mentally have the option to bail-out of a trip, even a day hike, if conditions are more than my gear/my body can handle.

That still, small voice (a.k.a. gut instinct) usually kicks in when you're about to make a bad move. If the feeling inside is to turn around or drop camp right where you stand, you should do that.

Flag as Inappropriate

Flagging Questionable Content Protects the Community at

In what way this content is inappropriate? Please check one:

More Details (Optional)

Submit answer


PLEASE REI! do not market your "waterproof" socks as vapor barriers. a vapor barrier sock needs to be NON-BREATHABLE for it to work properly (not gore-tex or neoprene).

Please use taped nylon if you are wanting to create vapor barrier socks. your feet will be slightly damp from your own sweat at the end of each day, and you will want to change out your liner socks each day too. your feet will be warmer with a non-breathable sock because you will not loose heat due to moisture transfer. Integral designs and RBH makes these, although they are easy to make out of plastic bags.


I am in recovery from immersion foot right now. I spent 17 VERY hot days rafting the Grand Canyon, with the usual foot abuse from the sun, sand, sandals, toe stubs...Then I went to Denali and in the course of a four-day workshop spent a day in wet leather boots. We slept in tent cabins, so my feet did not really warm up fully at night and the cool air was somewhat humid. I had been treating my desert abrasions with various salves and antibiotic ointments which included covering my gooey feet with socks at night. I had also sprained one ankle on the raft trip. My feet got very itchy then tissue began to slough off, leaving open sores. I went to a clinic and received the verdict. Ibuprofen, stronger antibiotic, an antifungal cream, elevation of feet above the heart, and time are the treatments recommended. I put cotton balls between the tips of my toes to provide a space for air to get through and I am trying to stay off my feet. But it is summer and hard to sit still. So I wear "slides" (slip-on flip-flops) and hope that recovery is swift (one week of treatment and vigilance so far) and complete. My feet are truly ugly and achey, with purplish patches and some weeping bumps and even the one that is more healed looks more like a dinosaur's foot than a person's. The CDC web site recommends NOT wearing socks at night because of sweating. Yep, dry feet and socks, waterproof boots, and paying attention are essential.


Unable to Post Comment

We were unable to post your comment at this time. Your opinion matters, so please try again later.

  • Most Recent
  • Most Commented

    No entries found

    No entries found