Nothing ruins a hike quicker than when you peel off your sock and find a gaping hole in your heel. On a multi-day or thru-hike, blisters can make the experience pretty miserable.
Having walked numerous miles over the years, I think I’ve become pretty adept at preventing blisters when hiking, although they do occasionally sneak up on me. Usually when I head off unprepared.
What Causes Blisters?
A combination of friction, heat and moisture causes blisters. The friction causes inflammation in the skin which then protects itself by filling up with fluid or sometimes blood.
This creates a sort-of cushion effect, protecting the skin below. For a scientific explanation, see Podiatry Today.
Top Tips for Preventing Blisters on the Trail
Before you head out
Your Hiking Boots
Select the lightest hiking boot or shoe that is suitable for the terrain. There really is no point in wearing those heavy leather mountain boots if the trail is relatively flat.
Of course, if you are going out in winter up a snowy peak, then you’ll need a warm boot.
Break in your boots. In fact, I’d go as far as to say, re-break-in your boots if you haven’t worn them in a while. Wear them regularly around the house and to the shops, get used to them.
Even if you feel a bit of an idiot wearing hiking boots to the pub.
If you are preparing for a multi-day hike, it’s essential to “train” your feet. They will take a battering stomping through the bush carrying you all day. Particularly if they are used to sitting idly under your desk!
Even if you have a regular exercise routine, it’s important to get out and about in your boots. The skin will toughen up if given enough time, becoming more resistant to blisters. That’s not to say that you want calluses to form.
A bit of walking barefoot out of doors, wearing your boots with a weighted daypack - even on a treadmill if you can’t get outside - will help toughen the skin.
Trim those nails. Not so short that you risk an ingrown toenail, but keep them trimmed short and without sharp edges. There’s nothing like a carved-up, blistered toe from the next-door nail rubbing on it to blacken your mood.
The Importance of Correct Socks
Personally, I’m a fan of using a good liner sock. Cotton socks are a big no-no, as they absorb moisture and your feet will end up a horrible sweaty mess in no time.
So leave the cotton at home, and do your feet a favor by getting hold of some hiking socks.
What are Hiking Sock Liners?
These are usually made of synthetic material that you would wear under your wool sock. They are lightweight, breathable, and do a good job of wicking the moisture away from your feet, keeping them dry.
You want a sock liner to be snug fitting but not tight. It’s no good if it is loose and bunches up causing friction and yet more blisters!
The outer sock will be somewhat dependent on the weather you are expecting on your hike. If hiking in winter, or in very cold conditions, you’ll need a thermal sock or a much thicker wool sock.
Hiking socks are designed to cushion your feet, and provided you get the right size, prevent bunching and rubbing.
Using this double-sock technique means that the socks will rub against each other protecting your skin from the friction that causes blisters.
Because nature does this best. Wool is much better at regulating temperature and with its wicking properties naturally draws moisture away from your feet. Select a light wool sock for summer hiking.
Remember that your feet will swell when they get hot - and at higher elevations. Your boots need to fit properly with enough room in the footbox for you to wiggle your toes - with your socks on.
If you are prone to very sweaty feet, it’s a good idea to bring along spare socks and change them during the day. Hot, moist feet will almost inevitably lead to blisters.
Similarly, if you plan to be fording rivers or hiking through muddy ground, change socks so your feet don’t get saturated.
When changing socks, it’s a good time to make sure no sand or grit has found its way into your boot, causing further friction.
Lacing your Boots
Not too loose, not too tight. Without cutting off your circulation, you’ll need to lace your boots as tightly as you can - particularly the boots that have ankle support. Loose laces mean that your foot moves around more in the boot, creating needless friction.
Hiking in Wet Conditions
If you are hiking in boggy or damp conditions, or need to do river crossings, you will need to be extra vigilant.
When your feet get wet, the skin absorbs the moisture and causes what is technically known as “maceration”, or “pruning”. Yes, that wrinkly-skin effect that happens when you spend all day in a swimming pool.
This causes the skin to soften, making it more susceptible to blistering. Not only that, but when your feet do eventually dry out, the natural oils of the skin have been depleted, which can cause painful cracks.
There are a few key items that can help prevent blisters. And others that don't really work so well.
What about foot powder?
Foot powder divides people. Some folk swear by it’s effectiveness at preventing blisters, but when it gets wet from sweaty feet it tends to clump and become quite abrasive. If you regularly use foot powder in ‘normal’ shoes, try it with your hiking boots before hitting the trail.
What about Hydrophobic Salve or anti-friction cream?
What? For a long time, before-I-knew-what-I-know-now, I used to slather my feet with Vaseline before putting on my socks.
This acts as a lubricant, preventing friction, helping to stop blisters.
However, whilst this still works, and I still use it occasionally, there are better products available.
If I’m going on a day hike, where I don’t expect to get my feet soaking wet, then a dose of Vaseline or a specific anti-friction lubricant does the job.
The problem with these is that they need to be reapplied regularly, as it tends to wear off. Vaseline has a habit of clogging the fibers of your socks.
There is a product called HikeGoo, which I used during an Everest Base Camp trek, which I found very effective. It didn’t clog my socks and I certainly felt no hotspots even after multiple days over tricky terrain. But it was rather greasy and hard to get off my hands.
If you are prone to sweaty feet, it would make sense to prevent them from sweating using an anti-perspirant, wouldn’t it? It’s possible.
However, you need to be careful of developing a sensitivity to the chemicals used in the antiperspirant before reaching for your favorite roll-on.
What to do when you feel a "Hotspot"
So you’ve got your boots, worn them everywhere for a few weeks to the amusement of family and friends, but an hour into your hike you feel a hotspot. What now?
As soon as you feel a “hotspot” developing - Stop. Immediately. Luckily you still have a few options available.
Rugged bushwalkers often swear by duct tape. I’m not a fan (unless you’ve got nothing else). The problem with using duct tape to cover an area that has either developed a blister or is threatening to, is that it doesn’t breathe.
This allows sweat to build up underneath the duct tape, loosening it and making the skin even softer.
Luckily the clever folks in the medical community have come up with some better options. Fixomull and Leukotape are readily available in most pharmacies.
What is Leukotape?
Leukotape and Fixomull are breathable, hypo-allergenic tape that are used for securing wound dressings.
Because they breathe, sweat does not build up underneath so it’s fantastic for areas prone to blisters or covering a hotspot before it becomes a blister.
Since using Leukotape I’ve been able to dispense with the more expensive and cumbersome blister plasters. I used to use moleskin but I found it to be too bulky if I needed to put it on in more than one area.
Once a blister has actually formed, it’s best to have a small patch of non-stick gauze under the leukotape to just cover the blister, otherwise when you pull off the tape, it’ll take your skin or “blister roof” with it.
Making a Moleskine “donut”
Once a blister has developed, and is painful, a technique that can be used is to take some moleskine, cut it into an ‘O’ shape, (a bit like a corn plaster) so that it surrounds the actual blister, before covering with another piece of moleskin, - or better still some Leukotape.
This can be effective, particularly on the toes. I’ve found on heels it’s just too cumbersome and often rubs off, making an already painful blister even worse.
Another interesting - but as yet untested by me - development is Hiker’s Wool. This is extra-soft Merino wool from New Zealand, that is placed in areas that are prone to hotspots.
Apparently, you simply pull off a little piece of wool, and tuck it into your sock. The natural lanolin in the wool prevents friction and also wicks moisture away from your foot. Coupled with a decent Merino wool sock, I’m going to give this a try next time I hit the trail.
Should you pop a blister?
Out on the trail, with the increased risk of infection, popping of blisters is not recommended. If you decide to do so, make sure you thoroughly disinfect the pin you use, and put antibiotic or antiseptic ointment on under the dressing.
Ideally, you don’t want to be in a position of having open wounds when you are out hiking.
If the blister is already split, you’ll need to take extra care to clean the wound and dress it, using an antiseptic and sterile dressing. Monitoring is important to prevent infection.
If the entire blister “roof” is off, you’ll need a hydrocolloid dressing, such as Compeed or Duoderm. During healing, the blister will weep, and the hydrocolloid dressing will maintain the wet environment essential to healing.(1)
It won’t stick to the skin (much) - and if you have a blister at this stage you’ll need to keep a close eye on it and seek medical advice if any sign of infection is apparent.
Before you hit the trail:
- Do your boots fit and are they “worn-in”?
- Have you done a few day-hikes to identify where hotspots are likely to develop?
- Do you have the right socks?
- Lace your boots tight, without cutting off circulation!
What to keep in your pack:
- Hiker’s Goo or Vaseline (keep reapplying Vaseline)
- Leukotape or fixomull
- Compeed blister plasters
- Dressings and antiseptic/antibiotic ointment
- Spare socks
If you follow this advice you should have no problems with blisters the next time you hit the trail. Happy feet means happy hiking!