Idea: Bedding to Keep You Comfortable

Ever woken up uncomfortably hot or cold? Maybe you wake up sweaty in the mornings? Why don’t we embed intelligence into bedding to keep people at an ideal sleep temperature? Using thermometers, moisture sensors, and/or light sensors (wet skin reflects differently) you could easily determine an occupant’s temperature and adjust accordingly. The adjustments are more tricky, I think. Perhaps you could raise the covers if people are too warm and tighten them if they’re too cold; or have heating and cooling elements in the bed; or control airflow over the bed.

Does this exist? If not, why not?! Are there better ways to detect the person’s temperature and adjust accordingly?