I’ve often wondered whether the tendency to sleep longer in Winter is due to less daylight or a decrease in temperature.
Over the last few days my experience has led me to the temperature being the cause. It’s been about 5 degrees Celsius overnight here in Perth for the last week. We don’t have central heating, so each room is generally a different temperature.
Given my sleeping habits on this challenge and the fact that I spend most of my time with the lights on, I think I can sufficiently control against the action of daylight. Obviously it would take a much longer experiment to be certain, but at this stage, I think its effect is negligible.
I noticed this week that when I’m in my study, where the heater is, I’m not unusually sleepy, but if I stay in the lounge room where it’s cold, I get really sleepy, really quickly and can’t snap out of it.
This obviously matches up with what we know of the circadian rhythm, where there’s been a noticeable change in internal body temperature coinciding with the two times we generally feel most drowsy (night time and early afternoon – think “siesta”).
It also explains why it’s so hard to fall asleep on hot Summer nights when it might be over 30 degrees Celsius (we don’t have air conditioning either). I also remember hearing stories of how people caught in snow blizzards would feel uncontrollable urges to fall asleep.
Another thing that’s very obvious – night caps (the cloth variety, not the alcoholic one lol) might really help you to go to and stay asleep. The standard configuration of pillow and rugs doesn’t seem to account for the loss of heat through an extremely exposed head. During the sleep challenge I generally sleep with all my clothes on (why get changed if you’re only going to be up 20 minutes later?) and most of my jumpers have hoods on, so I’ve been sleeping with a hood on.
Anyway, just a few interesting observations I thought I’d share.