Vests are the ultimate shoulder season layer. Like spring and fall, they bridge a contrast; they’re neither jacket nor mid layer, but something in between. It’s in those transitional seasons that vests function best — they can act as outer-layer or mid-layer in response to what the weather decides to do — but they shouldn’t be discounted for year-round wear, particularly not in winter.
Staying warm during the colder months is best accomplished by insulating the body’s core, a task that vests are explicitly designed to perform. Even when temperatures drop below zero, if you get your muscles moving — on a hike, ski tour or snowshoe trek for example — your body will heat up to the point where full coverage becomes overkill, unnecessary even. Outdoor companies know this — it’s why body-mapped jackets and layers that place all their insulation around the core and little or none around the arms and back exist.
Vests accomplish the same goal. But even when you aren’t getting active, a vest will act as a low-profile layer to provide additional warmth beneath a jacket. Wear one for an alpine ascent, on a lap of your local 5k loop or during your commute to work.