en retenant l'air

CONT: Une fermeture étanche autour du bord inférieur du vêtement augmente l'isolation en retenant l'air, ce qui permet une protection accrue contre les intempéries.

CONT: [The] Super 200 Trailwind Fleece Jacket warms you by trapping air, which is then warmed by your body heat.
CONT: The bottom of the fleece top is elasticised for a more secure fit. A tight seal around the bottom increases the insulation by trapping air, which enhances protection against the elements.