ThermoBall Boots

Find the right size boot

A boot should fit snugly and hold your foot securely in place, without causing pain or pressure points.

• Measure your feet and consult the brand’s ski boot sizing chart
• If possible, try boots on in person

Consider the last width

Last is the width (mm) of the inside of the boot at the ball of your foot.

• Narrower last: Ideal for narrow feet or those who want a tighter, high-performance fit   

• Wider last: Better for wider feet or those prioritizing comfort

Understand ski boot flex

• Softer: Comfortable and forgiving; great for beginners or smaller skiers

• Medium: Best for intermediate to advanced skiers; balances comfort and responsiveness

• Stiff flex: Ideal for expert skiers; prioritizes performance

Hiking shoe vs. hiking boot

• Hiking shoes
• Often lighter weight, lower cut, more flexible and more breathable
• Ideal for day hikes or backpacking with lighter loads
• Hiking boots
• Burlier, with stiffer uppers, over-the-ankle coverage and typically waterproof
• Ideal for multi-day treks with heavier loads

Types of hiking boots

• Day-hiking boots: Mid- to high-cut models that require less break in time; intended for day hikes or short backpacking trips with light loads
• Backpacking boots: Often over-the-ankle height and heavier-built with stiffer midsoles; designed to support multiday treks with heavier loads

Consider the lugs

• Deep, thick lugs improve grip
• Wider lug spaces sheds mud and offer good traction

Understand boot flex

• Soft flex: Comfortable; ideal for beginners or recreational riders
• Medium flex: Balances all-mountain performance and comfort
• Stiff flex: Maximum support for edge power and control at high speeds

Match riding style to flex

• All-mountain: Soft to medium for most riders; stiffer boots for racers
• Freeride: Stiffer for edge power and control at high speeds
• Freestyle: Softer for quick response and maneuverability in park terrain

Boot lacing system

• Dial lace: Uses one or two dials attached to cable for precise fit, higher cost
• Hybrid lace: Combines a dial system and traditional laces
• Traditional lace: Tried-and-true and easy to replace but can loosen during rides
• Quick pull: A single-pull lacing system that's fast and allows zonal tightening

Find a good fit

• Boots should feel snug and secure without cramping your feet
• It's OK for toes to barely graze the boot's toecap
• A snug heel fit is also key

Rent or buy?

• Rent if you have a one-time, guided trip planned
• Buy if you have multiple trips or long training season

Choose based on your activity

• Long approaches: insulated boots for warmth and broken-in comfort 

• Hiking, scrambling: lighter, three-season boots are versatile and lower-cost

• Mountaineering: durable, rigid, waterproof plastic shell boots are common as rentals 

After you buy your boots 

• Consider adding insoles for comfort and support
• Break them in before your summit attempt
• Find crampons that fit: either strap on, semi-automatic or hybrid
• Clean between outings
• Reapply water repellent when moisture absorbs instead of beads