Invent summerlight has been created by the x bionicreg developers specifically for use in the warmer weather worn next to the skin it exerts its air conditioning effect according to the intensity of the movement it cools when you sweat and warms when you are cold the boxers have a generous proportioned macrosphere system on the lower abdomen which ensures cooling without any risk of chilling it cools you down when you are sweating and warms you when your cool