The cause of their insomnia might be the change in weather but the solution might be as easy as opening a window. Fresh air seems to help many people fall asleep.
Usually during the warmer months we tend to open the windows of our home. Having a gentle flow of fresh air into the room feels relaxing while we sleep and if the weather is pleasant it almost goes without thinking that we keep the windows open, even if just a bit.
In the colder months that becomes a bit more challenging. As we glance out the window to see a frosty scene before us, we don't even contemplate the idea of opening a window when we go to bed. Then we find ourselves tossing and turning as the night quickly becomes morning, and we have to start our day without any rest and feeling the effects of that.
When our home is closed up for winter, it becomes a world all of its own. The air doesn't circulate well and the air quickly becomes stale. As we lay in bed trying to sleep, it is that air that hasn't been circulated and is essentially used that we are forced to breathe in. For some people that is enough to keep them from sleeping.
There are several ways you can get the air moving again even when the temperature is cold outside. A few suggestions that you might try are:
An air purifier. You can purchase these at many online retail outlets as well as at many hardware stores. Many are portable and these allow you to use the purifier in your bedroom at night and then take it with you to another room during the day.
A ceiling fan. Ceiling fans are designed with a dual purpose in mind. They help cool a room during the warmer months and then help with the circulation of air during the colder months. Although they do come with detailed installation instructions, you might be wise to hire and electrician to handle the job.
Your furnace. Most newer model furnaces are designed to keep the air in a home in constant circulation. They also keep the air clean and for a climate where the temperature dips very low, having an efficient furnace is very important.
If you do happen to live in a climate where the temperature doesn't dip too low, you may be able to keep your window open a bit the entire year. Keeping that constant flow of fresh and new air entering the room will help lessen your chances of developing insomnia, because your body won't be breathing in the same stale air night after night.