Helikon-Tex US Level 2 Thermal Layer — long-sleeve base layer

The Helikon-Tex US Level 2 is a long-sleeve thermal shirt designed as a first insulating layer for those operating in cold or variable conditions. Built from 95% polyester and 5% elastane, it weighs 303 g and sits against the skin as the foundation of a layering system, wicking moisture away from the body without retaining it.

The high polyester content actively manages moisture: during sustained effort, the fabric transfers sweat toward outer layers, keeping skin dry and reducing evaporative cooling during breaks. The elastane content ensures the fabric follows every position without tearing or bunching in the wrong places — a relevant quality when worn under padding or tactical gear.

Flat seams eliminate ridges that, under a pack or plate carrier worn for hours, turn into painful pressure points. Raglan sleeves move the shoulder seam toward the chest, freeing the joint during wide movements such as shouldering a rifle or climbing. Thumb loops hold the cuff in place when pulling on a glove or lowering the arm, but come with a trade-off: the sleeve is less adjustable in length than one without a loop, and those between sizes should check whether the sizing chart length works for their arm span. The chest zip lets you vent heat quickly without removing upper layers.

Key features

• Polyester-elastane blend that wicks moisture toward outer layers, keeping skin dry during exertion.
• Flat seams: no ridges to chafe under carriers, packs or belts worn over long periods.
• Raglan sleeves that free the shoulder during wide movements, with thumb loops to hold the cuff in position.
• Chest zip for adjusting ventilation without removing upper layers.
• Low weight of 303 g: adds no meaningful bulk even when stacking multiple layers.

In the box

• US Level 2 long-sleeve thermal shirt