A listener from Ontario, California wrote to A Moment of Science with a question her sons hadasked her.
一位来自加利福尼亚安大略的听众我们给写信询问她儿子们遇到的问题。
The boys wondered why is it that when you get sunburned you often feel chilled.
这些小男孩想知道为什么人晒伤的时候会觉得冷。
It really doesseem like a contradiction: you've been burned, but you feel cold.
这简直就是矛盾至极:你明明晒伤了，却觉得冷。
The answer to this seeming contradiction is in your blood.
这个看上去自相矛盾的问题的答案就在你的血液当中。
Sunburn is an injury to your skin, and your body's usual reaction to being injured is to enlarge theblood vessels in the damaged area.
晒伤表明你的皮肤受到了损伤，而通常人体应对损伤的办法就是使受创的血管扩张。
This allows more blood to be circulated near the injury, whereit can deliver cells to help heal the wound.
这使得更多的血液在伤口附近循环，同时血液中的一些细胞也会被输送到伤口附近，帮助伤口愈合。
Since sunburn is usually damage to the surface of your skin, the blood vessels in the area of theburned skin enlarge so that more blood is circulated there; this is where the redness comes from.
由于晒伤通常会损害你的皮肤表面，而晒伤部位的血管会扩张，使更多的血液在附近循环。这就是为什么晒伤部位会变红。
When you're sunburned a large area of your body is usually involved, so a result of so muchblood being near the surface of your skin is that you lose more than a normal amount of bodyheat through it.
晒伤通常会波及到人体的大部分区域。而大量血液聚集在皮肤表面附近的结果就是:你会散失比平时更多的热量。
Your brain tries to balance this loss of heat by activating reactions which attempt to conserveheat.
为了平衡损失，大脑尝试通过刺激人体作出某种反应来保存热量。
A common reaction is shivering, which is the body trying to generate heat in an effort tocompensate for the heat that is being lost.
该反应通常表现为颤抖，这一动作表明人体正试图产生热量来补充正在散失的那一部分。
So, even when your skin feels hot to the touch, you shiver and feel chilled as your body tries tomake up for the extra heat loss.
因此，即使你的皮肤摸一下都觉得发烫，但你还是会颤抖，觉得冷，因为这是人体正设法补充额外散失的热量。
