This is as simple as dropping the temperature in your house.
In many ways, our bodies are hardwired to an environment we no longer live in. We were adapted to being outdoors in the Savannah African grasslands. There, it gets colder at night with a radical temperature transition from daytime to nighttime.
In our modern world, we have climate control in our homes, offices, and cars. Our bodies don’t experience the fluctuation of temperature they’re waiting for. The movement patterns of our muscles (being active and engaged) are tied to that rhythm. When your body is staying at the same temperature day and night, your muscles are not totally activated. This is largely why it can be harder to be physically active, to train well, and recover. It’s also why you get random movements, tremors, or twitches when you’re trying to sleep at night. Your muscles don’t know if it’s time to turn on or off. The temperature contrast causes them to shut off, so they’re not moving around at night, agitating you.
So, what’s the answer?
The most practical step you can take is to adjust your thermostat. Many thermostats have automated settings where you can set different temperatures for different times of day and different days per week.
I live in the Sonoran Desert, so our air conditioning is running 24/7 much of the year. We have our thermostat set to cool at 71 degrees before bedtime. It’s an unconscious cue for me to know it’s time to start winding down to hibernate for the evening. If you’re using the heat in your home right now, use less heat. If you’re able to have your windows open to enjoy the fresh air and natural temperature changes at night, that’s great! Even if it’s rather chilly outside, open a window to cool the room.
Another way to “chill” is to jump in the shower, even if just for a moment. Any water temperature (except scorching hot) will work to take heat off your body, through your skin, by natural radiation.
Start to cool your house and/or jump in the shower about one hour before bed. This is when it’ll make the biggest difference.