Around the world, summers are getting hotter. Day and night temperatures are increasing. What impact could that be having on how we sleep?

在世界各地，夏季越来越热。白天和晚上的气温都在升高。这会对我们的睡眠产生什么影响？

Temperature and sleep are closely linked. Typically, our bodies cool themselves down before we sleep. One of the main ways that we do this is by widening blood vessels near the skin to allow heat to dissipate. In hot weather, this process becomes less effective as it is more difficult for heat to be transferred. One of the body's mechanisms to speed up this process is by allowing sweat to evaporate. However, in humid conditions it's harder for evaporation to take place. If the body is unable to cool down, then it's more difficult for people to fall asleep and more likely that sleep patterns can be disrupted.

温度和睡眠密切相关。通常，我们的身体会在睡觉前自行降温。我们做到这一点的主要方法之一是加宽皮肤附近的血管，以便热量散发。在炎热的天气里，这个过程变得不太有效，因为热量更难以传递。身体加速这一过程的机制之一是让汗水蒸发。然而，在潮湿的条件下，蒸发更难发生。如果身体无法降温，那么人们就更难入睡，而且睡眠模式更有可能被打乱。

This means that it's important for us to try to manage the temperature of the environment that we sleep in. While it can be costly, air conditioning is a useful tool to keep our sleeping environment cool. Managing ventilation is also important. During the hottest hours of the day keeping windows and curtains closed can stop hot air and heat from sunlight entering our homes. At night, once the temperature has dropped, opening windows can allow cool air to come in and reduce the temperature in our homes. Fans can help to speed up cooling, as long as air temperatures are low enough. They become less effective in hotter conditions.

这意味着我们必须设法管理睡眠环境的温度。虽然成本可能很高，但空调是保持睡眠环境凉爽的有用工具。管理通风也很重要。在一天中最热的时候，关闭窗户和窗帘可以阻止热空气和阳光产生的热量进入我们的家。晚上，气温下降后，打开窗户可以让冷空气进来，降低家里的温度。只要气温足够低，风扇就可以帮助加速冷却。在较热的条件下，它们的效率会降低。

It's not just rooms that we can cool down. Using breathable bedding and sleepwear makes it easier for our bodies to regulate temperature. While it may seem counter-intuitive, it can be beneficial to have a warm bath or shower before sleep. Warm water can cause more blood to flow to our skin. Once you get out of the bath or shower, this means that you cool down more quickly. Another tip suggested by sleep experts Kevin Morgan and Lisa Artis is to cool your socks in the fridge and then put them on before going to sleep. They also say that it's important to try to keep to your usual sleep routine to avoid disruption to your sleep habits.

我们不仅仅可以给房间降温。使用透气的床上用品和睡衣可以让我们的身体更容易调节温度。虽然这似乎有悖常理，但睡前洗个热水澡或淋浴可能是有益的。温水可以使更多的血液流向我们的皮肤。一旦您离开浴缸或淋浴，这意味着您会更快冷却。睡眠专家凯文·摩根和丽莎·阿蒂斯建议的另一个建议是将袜子放入冰箱中冷却，然后在睡觉前穿上。他们还表示，尽量保持平常的睡眠习惯很重要，以避免扰乱您的睡眠习惯。