It's Hot, Why Can't I Sleep?

Have you ever wondered why your body has a habit of waking up at the same time even if you miss your alarm? Have you ever wondered why? I think most of us know that our bodies have an internal clock and it naturally tells us when to wake up and when to go to sleep. It’s why if you are in the habit of staying up until 2 a.m. and waking up at 10 a.m. you will have an awfully hard time falling asleep at 10 p.m. and why if you go to bed at 9 p.m. you will have an awfully hard time staying awake past 10 p.m. What I would like to do is jump into a little about one of the factors that regulate this clock and how you can make sure you are getting a good night sleep.

The factor I would like to talk about is one that you may not have really thought about, or at least not in the right manner. This factor is temperature. You may have experienced that it’s much harder to fall asleep in a warm room than in a cool room, but have you ever wondered why? It turns out that our bodies fluctuate in temperature throughout the day and our bodies use that fluctuation as part of our internal clock. The temperature fluctuation is small (within 1 degree), but it has major effects on our sleep and wakefulness. Our temperature changes follow the same path each day. We are the coolest around 2 hours before we wake up and warmest during the midpoint of our being awake. So if you wake up around 8 a.m. you will be your coolest around 6 a.m. and your temperature will peak in the mid-afternoon, before slowly decreasing into the evening. These temperature fluctuations follow a 24-hour cycle and are one of the major reasons why we feel sleepy when we do and help us determine when to wake up. 

So why does any of this matter? Well, these temperature fluctuations can be changed by our external environment and, unsurprisingly, we often do mess them up in modern life. For the vast majority of human history, our bodies simply followed the rhythm of the day. Dwellings were usually fairly similar in temperature to the temperature outside. The nights were cool and as the sun would rise, so would the temperature in the dwelling. Our bodies would keep this as part of its internal clock on when it was time to sleep and when it was time to wake up. Unsurprisingly modern life has sometimes played havoc with this system. Thermostats attached to furnaces and air conditioning units have allowed us to keep our homes at whatever temperature we choose. This can start to mess with our internal clock and make it harder to fall asleep at night or wake up in the morning. Fortunately, many of our thermostats have another nifty option, which is the ability to program them to be cooler at night and warmer during the day. This falls in line with what our bodies expect and will help prepare them to sleep properly and also to wake up properly.

One last thing I would like to mention about temperature and sleep is how we can use it to our advantage. There are a couple of things that you can do to really boot your body into the right mode for either sleeping or waking up and also a couple that might be hindering you. Showers! Are you taking a cold or a hot one in the morning? From what I just said, you might think hot shower in the morning and a cold shower in the evening. However, turns out it’s the exact opposite. If you jump into a cold shower in the morning, sure the shock will wake you up, but it actually causes your body to react by raising its temperature this promotes long term wakefulness. Taking a hot shower, unfortunately, causes your body to start cooling itself and actually promotes sleepiness.