While it’s possible to catch a viral illness any time of the year, winter seems to bring an influx of sickness. Flu shots are normally given in anticipation of seasonal spread;
尽管一年四季都可能得上病毒性疾病，但是冬季似乎是疾病的高峰期。为了应对疾病在冬季的大肆传播，人们通常会接种流感疫苗。

We often think of cold weather bringing people indoors as a big reason why colds and the flu seem to spread, but is that the only reason? Or is it something else?
我们通常会认为由于天气寒冷所以人们都呆在室内是造成感冒和流感传播的一大原因，但是这是唯一的原因吗？是否还有其他因素导致冬季容易患感冒和流感？

While it’s certainly true that spending more time indoors can put you in closer proximity to others and thereby raise the risk of transmission, there are other factors at play. According to the National Institutes of Health, the lipid (or fatty) coating of influenza cells tends to turn into liquid at higher temperatures, making it less stable and transmissible. In colder weather, however, the lipid membrane remains intact, allowing for a sturdier and more persistent virus. When it comes in contact with the respiratory tract, the coating dissolves and begins to infect its host.
可以肯定的一点是，在室内的时间变长意味着你和他人会更近距离接触，因此，疾病传染的风险也随之增加。但是除此之外，还有其他因素也在发挥作用。根据美国国家卫生研究院的解释，流感细胞的脂质外层在温度较高时会变成液体，因此其稳定性和可传播性也就随之减弱。但是，当天气较寒冷时，脂质薄膜就会保持完整，并从而使病毒更加坚固和持久。当流感细胞接触到呼吸道时，薄膜会融化并开始感染宿主。

That’s not the only way viruses can benefit from cooler temperatures. Winter also means less humidity in the air, both indoors and outside. Less moisture means viruses can travel farther and remain in the air longer without binding to water molecules. Less indoor ventilation can also lead to stale air and persistent, lingering germs.
这并非是病毒从冷空气中获得的唯一好处。冬季还意味着户内和户外的空气湿度降低。湿度减少意味着病毒可以传播得更远并能够更长时间地保持在空气中并且不与水分子粘合。室内通风不足也会导致空气污浊并且导致细菌持续存在。

What about physiological reasons? It’s possible that cold weather may impact our immune systems. A recent study in The Journal of Allergy and Clinical Immunology looked at the possibility of immune defense in the nose growing less effective as temperatures drop, though only four subjects were studied and no firm conclusions were drawn. There’s also no general consensus over whether simply being cold affects our immune systems. Although it’s possible that fluctuating body temperatures can affect our ability to fight off illness, heading outside with wet hair or grabbing the mail in a T-shirt are unlikely to be major factors in getting sick.
那么，生理方面的因素呢？冷空气可能会影响我们的免疫系统。《过敏与临床免疫学》期刊最近所发表的一项研究发现鼻腔内的免疫防御能力会随着气温下降而减弱，尽管只有4名受试对象参与了研究并且没有得出肯定的结论。目前关于我们的免疫系统是否仅仅会由于寒冷而受到影响，目前还没有一致的意见。尽管变化的体温可能会影响我们抵御疾病的能力，但是头发没干就出门或者穿着短袖去拿邮件并非是导致我们生病的主要原因。

While winter may increase your risk of catching something unpleasant, the same general principles to stay healthy still apply. Frequent handwashing can help reduce the spread of germs, as can regularly disinfecting surfaces; try to avoid sharing utensils or drinking glasses with others, too. Vaccinations can also lower your risk of infection.
尽管冬季我们更有可能生病，但是还有一些原则可以帮助我们保持健康。比如，经常洗手可以减少细菌的传播，同样定期给表面消毒也有作用；避免和他人共用餐具或水杯。疫苗也会减少感染疾病的风险。

Utensils：餐具

来源：Mental Floss

编辑：上海译锐翻译