Astronomy tends to be a chilly hobby.
It's easy to stay warm on cold winter nights if you dress appropriately and take a few common sense precautions.
There are three possible strategies for dealing with this fact – stay inside when it’s cold, pretend it’s not cold and suffer accordingly, or dress appropriately. You can probably guess which strategy I prefer!
In winter, you need to wear extra clothing everywhere. No jacket will keep you warm if your head is bare so get a beanie, or if you're wearing nothing but blue jeans on your legs slip on a pair of track pants too.
There are a lot of other things you can do to stay warm at the telescope.
One trick I use is to stand on a thick flattened cardboard box. Paper is a good thermal insulator and will keep the heat in your body longer.
Your body burns lot of calories in cold weather, and a high carb snack can work wonders to warm you up as well.
Hot drinks are particularly useful. When I drink a cup of hot cocoa in cold weather, I feel a surge of warmth spreading through me from the inside out. Keeping the internal organs warm is essential while hands and feet are dispensable.
Your body cuts off circulation to the extremities as soon as its core gets cold.
If you want to use gloves or mittens here’s a little trick. Buy a cheap pair and cut the last few centimetres off each finger. This allows you to use your telescope controls and handle your eyepieces. Funnily enough, your fingers won’t get cold. True!
Putting weight on your feet cuts off the blood flow, sitting is much better than standing.
Wiggle your toes and taking periodic breaks for a short jog works wonders all around, warming you up and getting your blood flowing.
OK, it’s about this time your telescope will start getting wet.
That’s dew falling on it and it ruins your viewing – but its not necessarily the end of your night. You can easily make a ‘dew shield’ to put over the end of your telescope.
A piece of 5/8-inch foam rubber rolled into a short tube makes a dew shield that’s cheap, durable, and very lightweight.
Lastly, consider your eyes. Allow your eyes to become ‘dark-adapted’ before trying to observe faint deep sky objects. This takes time, typically 30 minutes under truly dark conditions. Unfortunately, it only takes seconds to ruin your dark adapted eyes by looking into a bright light again.
Since red light is easier on dark adapted eyes, astronomers use red light to work around a telescope or read star maps. You can either use a torch with red cellophane over it or coat the lens with several layers of red nail polish. Now, go out and enjoy the best skies in the world.