What Our Gearhead(R) Experts Are Saying: "I reach for the Summit Thermal Jersey when I need something warmer than a jersey but more breathable than a shell. The grid fleece is great at keeping heat in and sweat out, and I love how the hood fits under a helmet on cold starts." The PEARL iZUMi Summit Thermal Jersey is our go-to for variable temps and big-mile days in the dirt. Built with a lightweight, grid-fleece interior, it traps warmth while breathing efficiently-keeping us dry and focused no matter how cold the morning starts. The articulated fit and extended rear hem are made for bike movement, and the slim-fit hood slips neatly under a helmet when we need that extra layer of insulation on brisk climbs or windy descents. Whether we're riding it solo in the fall or layering it under a shell for deep winter missions, the Summit Jersey brings trail-focused versatility to every ride. With three zippered pockets and a two-way front zipper for easy venting or rear-access reach, it balances thoughtful storage and performance-driven design to match every season's pace.