"The optimum room temperature for sleeping is around 65 degrees Fahrenheit (about 18 degrees Celsius), so make sure you check the thermostat before dozing off. "

I keep reading this recommendation, which is unrealistic. Everyday there is pressure from many sectors to keep our a/c at 78 degrees, lest we destroy the planet. The energy cost to maintain a 65 degree sleeping temperature is too much, people cannot afford it! I maintain mine at 75 degrees in the summer in a new energy efficient home in a southern region, and the bill is still a bit high. I cannot imagine what it would be like to keep it at 65 degrees in the southern or western parts of the USA, even if it only during nighttime.

While that temperature may be optimal for sleeping, it is not for energy consumption, the planet, and our wallets.