The moment Treasure Valley summers hit triple digits, the shoes come off and the sandals come out. Flip-flops are practically the official footwear of a Boise summer — but that freedom comes with a price. Most of the "sudden" foot problems I see between June and September trace back to one thing: footwear that offers almost no support.
The good news is that you don't have to choose between comfortable summer feet and sandal season. Here are the most common warm-weather foot complaints I treat, why they happen, and how to keep enjoying the Greenbelt, the farmers market, and the lake without paying for it later.
Open-back sandals let the fat pad under your heel spread out with every step. Add dry Idaho summer air and a lot of barefoot time on hot pavement, and the skin around the heel thickens, dries, and splits. Mild cracks are a cosmetic nuisance; deep ones (fissures) can bleed and become an entry point for infection.
What helps:
A deep heel fissure can become a wound that's slow to heal. If you're diabetic or have reduced sensation in your feet, don't self-treat — have it looked at. See our approach to diabetic foot care.
This is the big one. Flat, flimsy sandals have no arch support and no shock absorption, so the plantar fascia — the thick band along the bottom of your foot — takes the full load. Wear them all day, every day, and that tissue gets irritated. The classic sign is a sharp, stabbing heel pain with your first steps in the morning.
That's plantar fasciitis, and it's the single most common cause of heel pain we treat. To toe a flip-flop on, you also grip with your toes constantly, which fatigues the small muscles of the foot and can aggravate tendons. If your heels or arches ache after a day in sandals, your shoes are likely the culprit.
Summer doesn't cause bunions — they're largely structural and often genetic — but sandal season can make an existing bunion hurt more. Narrow, strappy sandals press directly on the bump, and walking more on hard surfaces increases the load through the joint. If the base of your big toe is red, swollen, or aching by evening, the sandal's fit is probably to blame.
A sudden, intensely painful, hot, swollen big-toe joint — especially overnight — is a different story and may be gout rather than a bunion. That one is worth getting checked promptly.
Open-toe footwear leaves your feet exposed. Every summer we see broken toes from stubbing them on furniture or curbs, cuts from glass and rocks at the lake or river, and surprisingly nasty burns from hot pavement and metal dock surfaces. A toe that's badly bruised, crooked, or too painful to bear weight on may be fractured rather than "just jammed" — see our page on foot & ankle injuries if that sounds familiar.
Warmth and moisture are exactly what fungus loves. Shared surfaces like pool decks, locker rooms, and gym showers are common sources, and sweaty feet in closed summer shoes do the rest. Keep feet dry, rotate your shoes so they fully dry out between wears, wear sandals (the supportive kind!) around public pools, and treat itchy, peeling skin early before it spreads to the nails.
You don't have to give up sandals — you just have to be a little choosier. When you shop, look for:
Save the dollar-store flip-flops for short trips across the pool deck, not all-day wear. And if you have a foot shape that's hard to fit — bunions, flat feet, high arches — custom orthotics can be paired with supportive sandals so you get summer comfort without sacrificing your arches.
Make an appointment if you have heel or arch pain lasting more than a week or two, a deep heel crack that won't heal, a bunion that's interfering with daily activities, a sudden hot and swollen joint, or any toe injury you can't bear weight on. Early care is almost always simpler and faster than waiting it out.
Sandal season and healthy feet aren't mutually exclusive. Most summer foot problems come down to support — choose footwear that actually holds your foot, keep your skin moisturized, and protect your toes. If something does flare up and isn't settling on its own, it's worth getting it evaluated before fall.
Dr. Clark Johnson is a board-certified foot and ankle surgeon at Treasure Valley Foot & Ankle in Meridian. If summer footwear has your feet aching, request an appointment or call (208) 272-9253 — we'll help you get comfortable again, just in time to enjoy the rest of the season.
From heel pain to bunions, we'll find the cause and get you back to enjoying the season.