So I’m a volunteer wildland firefighter with the Volunteer Wildfire Services. As part of compulsory PPE we are required to wear firefighting boots (Bova boots). My standard “everday” shoe size is 5. When I hike or trail run I size up to a 6. So my firefigthing boots are also 1 size bigger.
What I have found is (especially after a long day/night out) is that the balls of my feet are rather tender. As far as my knowledge stretches it indicates that my feet are slipping in my shoes. I currently have a “decent” blister on the side of the ball of the foot.
The first thing I changed is the insole as the initial insole got hardened out quite quickly. I also wear two pairs of thick socks. Adding a third pair of socks doesn’t seem like a solution.
So I’m wondering - are there some insoles that are “extra thick”? Or perhaps a fancy lacing technique that I am not aware of?
I’d like to attempt some other measures before forking out money and “down sizing” to a 5.
Is the blister on the inside edge of your foot, on the edge of the ball on the big toe side? If so, I used to get those when my boot’s toebox wasn’t wide enough and the edge of the insole would rub on the side of the ball of my foot. I found that double socks (which you’re already doing) and an anti-pronation insole helps.
I second Arno’s recommendation about your boots possibly being too narrow. Another suggestion is to instead wear a thin liner sock and thicker outer sock, rather than two pairs of thick socks. This might give your feet more space and also prevent as much sweating. Sweat is one major cause of blisters. I’ve found the best combination to be synthetic liner socks made of wicking material (something like coolmax/drynamix) and outers of mohair or merino wool. The liners wick moisture from your feet and transfer it to the wool socks, keeping your feet dryer.