Mobile Warming Primer Shirt And Summit Vest Review

Staying warm and comfortable without the wires or bulkiness.

The close-fitting heated Primer Shirt is meant to be worn as a base layer and comes in two styles: crew neck and turtleneck.
The close-fitting heated Primer Shirt is meant to be worn as a base layer and comes in two styles: crew neck and turtleneck.Mobile Warming

Mobile Warming’s stuff has been on my radar for some time now—portable heating solutions without any awkward, annoying wires snaking around your torso to hamper freedom of movement? Sign me up. When I finally acquired some of their gear in the form of the base-layer Primer Shirt and mid-layer Summit Vest, I also noticed a Fieldsheer logo on the box. Fieldsheer has been in the motorcycle gear game for over 40 years now, but I wasn’t aware they were connected with Mobile Warming’s heated-clothing technology. To my mind, it sounded like a win-win.

The conveniently low-profile 7.4 volt battery pack slips into a built-in pocket and plugs into the lead.
The conveniently low-profile 7.4 volt battery pack slips into a built-in pocket and plugs into the lead.Andrew Cherney

Men’s Primer Heated Shirt

First up, the shirt. The Primer package came with the heated shirt, a 7.4 volt lithium-ion battery and an AC battery charger. Shirt construction consists of a four-way stretch poly-spandex blend that’s comfortable on the skin while allowing for a full range of motion, plus it’s moisture-wicking, making it a nice fit for the outdoor activities I like to think I’m active in. I could wear it not only riding, but while skiing, snowshoeing or heck, even axe-throwing (yea, it’s a thing out here) without having to prewire and plug in. In fact the company is making a push into the ski and snowboard markets with this whole line of Bluetooth-based apparel. Smart.

The Primer baselayer packs integrated heating panels powered by the company’s lightweight 7.4-volt Far-Infrared Heating System, which is made up of three heating elements; one on the back and two on the chest. Plug the shirt lead into the battery pack, stuff the pack into the shirt’s built-in pocket, download the app, and you’re good to go. The modern battery design and charging circuitry along with the advanced high-density heating panels do the rest.

The system claims to deliver temps ranging from 135 degrees Fahrenheit on the high setting to 90 degrees Fahrenheit on low. On high, you can expect to get 2.5 hours of heat per charge, and on low, MW claims up to 11 hours. We haven’t worn the shirt for more than 5 hours at a time, so we’ll see how it pans out on longer days. You can adjust temperature with either the built-in rubberized button positioned near the shirt’s hem (you can toggle through four heat settings) or via the Bluetooth 4.0 control on the MW Connect app (available on iOS or Android), which lets you scroll through all connected Mobile Warming devices on your smartphone and adjust heat levels to your liking. The app also displays battery charge levels and will update your garments when new firmware comes out.

The rubberized button positioned near the hem acts as an on-off switch as well as a power controller. You can toggle through the heat settings from there, or via the MW app on your device. Either way is uber-handy.
The rubberized button positioned near the hem acts as an on-off switch as well as a power controller. You can toggle through the heat settings from there, or via the MW app on your device. Either way is uber-handy.Andrew Cherney

The app works as advertised, pairing easily with the garment and making it a cinch to sync and control heat. In fact, as far as user-friendliness goes, the Primer pretty much hits the target, with a close (and fairly true) fit, easy to operate controls and unobtrusive tech. The battery pack is slim and tucks away neatly, with the recharge time of 3.5 hours inline with my expectations.

It’s in the details that I found some things wanting. First was the heat level, which came on strong for the first few minutes, but then faded away to a subtle, barely noticeable warmth, regardless of the level selected. I could also detect more warmth on the right panel side than the left, with the wiring of the heat elements feeling asymmetrical, though I’m willing to forgive that—there’s not much room to configure wiring on a shirt. It also may be due to the fact that because the Primer is a base layer, any kind of heat feature next to skin has to err on the side of caution. That said, other details were more off-putting, especially in light of the $159.99 asking price: while the skin-side fabric was generally all-day comfortable, there were issues with the crew neck collar material, especially its shape retention and comfort. Parts of that fabric felt scratchy next to the skin, and the neck trim had lost some of its shape after only 3 weeks—some sort of accordion panels or flexible material could have made fit more snug and comfortable and help the collar stay shaped.

The MW app tracks individual garments, their battery charge and heat settings. The red (highlighted) icon indicates the highest heat setting. If you can tolerate minor chafing, this shirt does a solid job combatting the chill.
The MW app tracks individual garments, their battery charge and heat settings. The red (highlighted) icon indicates the highest heat setting. If you can tolerate minor chafing, this shirt does a solid job combatting the chill.Andrew Cherney

Other than that, I’m pleased with the Primer shirt as a concept—it’s a versatile, non-bulky insulating layer that keeps you warm with minimal fuss and without tangled wiring to fight through. I love that feeling of freedom, though with the Primer sitting right next to skin, I expected a more premium feel and attention to detail. That said, cost is in line with most of the battery-powered competition, and actually less than the majority of wired gear out there (even minus the controller). I have no doubt Primer Version 2.0 will address comfort and fit issues and refine the wiring, so I’ll recommend it -- with some caveats.

The Summit Vest brings a more robust heating system, a water-repellent outer and a nice, cushy duck down inner core.
The Summit Vest brings a more robust heating system, a water-repellent outer and a nice, cushy duck down inner core.Mobile Warming

Men’s Summit Vest

The Mobile Warming/Fieldsheer Summit Vest, meanwhile, turned out to be a more evolved piece of apparel. Fit, feel, and comfort was more refined than the Primer shirt in nearly every area, with the warming elements feeling more effective and the materials more appropriate, finished and pleasing to the touch. The zipper closes positively, the tall collar feels perfectly plush on your neck, and the puffer-vest fit is snug but forgiving. Except for the somewhat bulky battery, I could see wearing this piece of gear every day during wintertime, and on a variety of outdoor activities to boot. The Summit Vest uses Mobile Warming’s same Bluetooth-enabled tech but in more robust 12 volt form, and therefore utilizes a larger 12 volt 5200mAh lithium-ion battery pack, which is definitely noticeable for its heft. The lightweight, 100 percent nylon outer shell though, is super-comfy, water resistant and covers a 500-fill 85/10 duck down core that kept me warm on rides below 50 degrees Fahrenheit even without the heat on. The Summit incorporates two large heating elements on the back and two on the chest, delivering temps from 135 degrees F on the high setting to 90 degrees F on low. High delivers up to 2.8 hours of heat, with 11 hours available on low. That hefty, all-new rechargeable 12 volt lithium-ion battery includes a USB port to charge mobile devices and a powerful built-in LED flashlight, but we’d forego those amenities for a smaller footprint. As with the Primer, the MW app lets you change temps and levels on the Summit wirelessly, or physically using the integrated touch control button, and we got a nice, even, all-over warmth with most applications. We were also stoked to discover a well-designed combo of interior and exterior pockets, both zipped and open, and the Summit even packs into its own stow bag (included). I’ve only had it for a few weeks so we’ll see about durability but with a non-binding, plush fit, good looks, and nice details, it’s become pretty much part of my daily winter wear.

Large panels on the chest give off effective levels of heat, but a demerit goes to the bulky 12 volt battery pack; it’s hard to hide and you can definitely feel its weight and size.
Large panels on the chest give off effective levels of heat, but a demerit goes to the bulky 12 volt battery pack; it’s hard to hide and you can definitely feel its weight and size.Mobile Warming
Comfy and warm whether you power it on or not, the Summit Vest turns out to be a nice addition to the outdoor gear arsenal, no matter what your activity.
Comfy and warm whether you power it on or not, the Summit Vest turns out to be a nice addition to the outdoor gear arsenal, no matter what your activity.Andrew Cherney

Primer Men’s Shirt

$159.99

Available in S, M, L, XL, 2XL and 3XL

Summit Men’s Vest

$219.99

Available in S, M, L, XL, 2XL and 3XL