Although 78⁰ F is a good temperature for energy savings and comfort when you are home and awake, it is not ideal for slumber. In fact, bedroom temperatures that are too hot or too cold can result in a restless night. A general recommendation is that the optimal temperature for sleeping is between 60⁰ and 67⁰ F, regardless of the season outside3.
To help ensure a better night’s rest, consider re-setting your thermostat before you go to bed, leaving enough time for the temperature in your bedroom to adjust.
If you have a programmable thermostat, you may want to schedule it to automatically reduce the temperature during the times you are normally asleep.
If it works for you and your climate, try opening a few windows. This method will depend upon having milder, cooler outdoor temperatures, and offers a more energy-efficient, but less precise, option for achieving the targeted 60⁰ - 67⁰ F. Be sure to close the windows in the morning to seal in the cooler air.
The above recommendations are for a typical adult. Keep in mind that infants and small children should be in rooms with a slightly higher temperature to ensure better, more restful sleep.
3 See Cleveland Clinic