Dr. Neil Stanley, the former chairman of the British Sleep Society, is warning people that sleeping in a room that’s too warm can lead to disturbances in sleep which tend to cause nightmares. Dr. Stanley says one’s room should be between 61 and 64 degrees Farenheit. He said, “If you’re sleeping in a room which is too warm, your body’s core temperature is unable to lose (enough) heat and your sleep will be disturbed. If you’re sleep deprived, we see greater sleep intensity – and that in turn leads to greater brain activity while you’re dozing. That causes you to dream more, for your dreams to be more vivid, and for you to remember your dreams. And, unfortunately, that goes for nightmares, too, which can be intense.