Your blood vessels constrict to keep heat from radiating off the surface of your skin, and you get the goosebumps.

你的血管开始收缩 阻止热量从皮肤表面散发，然后你开始起鸡皮疙瘩。

Most heat loss occurs when unprotected surfaces radiate heat away from the body.

热量散失大多由于体表未经防护而向体外放射热量。