Do you think there is a benefit to having natural rather than synthetic dyes and fibres, such as wool?
Ideally, your sleep environment which includes your bed and bedding should help to keep you cool and not cause you any allergies or pain. It should also be free of harmful chemicals and allow for a good air quality and ventilation. I think it the main thing is to create an environment that you feel comfortable in.
What are your thoughts on heating and air conditioning on the quality of your sleep?
As a species, we evolved outdoors and not in well-insulated houses. That means our physiology (biologically speaking we are still very much cavewoman and caveman) is adapted to the natural change in temperature across the 24-hour day. A cooler bedroom is therefore better for sleep. This allows your body temperature to drop which opens these-called ‘sleep gates’.
But of course, you should not be freezing because that will make falling or staying asleep harder. Around 18C is a good guideline. Keep the bedroom well ventilated as this may improve sleep quality and possibly next-day performance.
Some people like sleeping with open windows (this can also help keep the air temperature low during the summer). However, there is also noise pollution to consider. Something I do is keep the bedroom door open instead of the window because of the street noise. And where privacy is a problem a fan might help.