Merrell Thermo Overlook 2 Tall WP Winter Hiking Boot Review

The Merrell Thermo Overlook 2 Tall WP is an insulated 400g waterproof/breathable winter hiking boot rated to -40F/-40C. These unisex boots (w/ men’s sizing) come up to mid-calf for maximum heat retention, they have a seamless wraparound waterproof rand, fleece lining, and a gaiter ring above the toes. A pronounced forefoot rocker (curve) makes them great for hiking and they have enough of an arch under the sole to run a gaiter strap if you wear high gaiters in winter.

But what sets the Thermo Overlook 2 Tall apart from other insulated boots is their comfort. The fleece lining is warm and well-cushioned, making them exceptionally cozy for all-day comfort in freezing temperatures. The leather uppers are supple and the boot is wearable out of the box with virtually no break-in. The sizing runs about a quarter size small. Wide sizes are not available and while the toe box is roomy, it’s not as high volume as other brands like KEEN and Columbia.

Specs at a Glance

• Temperature Rating: -40F/-40C
• Height: Mid-calf
• Waterproof/Breathable: Yes
• Gender: Unisex
• Sizing: Runs a quarter size small
• Insole: Wool covered foam
• Weight: 2 lbs 15.4 oz/pr (men’s size 10.5)

The Merrell Thermo Overloop Tall 2 WP is the kind of insulated boot you want for long winter hikes when your trips start before the sun comes up and end after it goes down. Rated to -40F/-40C, they are insulated with 400g synthetic insulation, which is a highly compressible synthetic insulation similar to Thinsulate and used in many of  Merrells’s products. These Thermo 2 Overlook Tall 2 boots are also mid-calf height, which traps more body heat than mid-ankle height insulated winter boots which cover less of your lower leg (See: 200g vs 400g Insulated Winter Hiking Boots).

The upper cuff and tongue are covered with a soft fleece liner while the exterior is covered in leather with ballistic nylon in high flex areas such as the tongue. The bottom half of the boot has a wide seamless wraparound rand that provides great toe and side protection while helping to ensure that the boots stay watertight for the long haul. While that makes them look a little like PacBoots, (See: The Problem with PacBoots), they are anything but, with an aggressively rockered and curved sole which makes it easy to walk and hike in them.

The Merrell Thermo Overloop Tall 2 WP’s have beefy Vibram outsoles that provide great traction on a variety of surfaces including slush, dry snow, wet snow, and wet leaves. I’ve had these boots for over a month and they grip well on all of those surfaces, although there’s no substitute for good hiking footwork.

Merrell includes thermal insoles with the Thermo Overloop Tall 2 WP boots, which are covered in wool for warmth but do not have a reflective aluminum coating. The insole is easily removed if you want to replace them with a more durable or supportive insole like Superfeet.

There is also a noticeable arch in the boots, worth mentioning because most winter boots have such poor arch support. I got used to it very quickly, but it is a distinctive departure from the norm. If the arch is too much for you, try removing the boot’s wool-covered insole and replacing it with a flatter one. I’ve found that that makes the arch much less noticeable.

The Thermo Overloop Tall 2 WP boots have an exaggerated front toe kick for toe protection and a reinforced heel counter to lock your heel in place and prevent pronation. Ridges on the back of the heel help keep snowshoe, crampon, or microspike straps from slipping down and off which is a real plus for more technical winter hikes when traction aids are required. The boots also have enough of a mid-sole arch that you can wear gaiters with a thick stirrup strap, like OR Crocodiles, without worrying about wearing them down from excessive surface abrasion.

There’s minimal time required to break in the Thermo Overloop Tall 2 WP boots which are soft and pliant out of the box. While they are waterproof/breathable, I’d still encourage you to treat them with a product like Nikwax Leather Waterproofing Wax to coat the seams at the junction of the leather uppers and the wraparound rand.

Recommended Insulated Winter Hiking Boots

Recommendation

Merrell Thermo Overlook 2 Tall Waterproof Boot 400g winter boots are ideal for men and women who want or need very warm winter hiking footwear. Rated to -40F/-40C, their high mid-calf height helps lock in warmth while a fleece-lined collar and gusseted tongue provide both comfort and additional warmth. Their thick soles provide excellent insulation from the cold ground and deep 5mm lugs provide good traction over a wide variety of surfaces. The sizing is unisex (ie. men’s) and runs about a quarter size small in my experience. These boots are wearable out of the box and require virtually no break-in period, but like all winter boots, it’s best to gradually ramp up your hiking distance and to wear them with winter traction (microspikes and snowshoes) to identify any potential hot spots, so you can tape around them with Leukotape before your hikes.

Disclosure: The author purchased this product.