What is the ideal temperature for sleeping?

nbcdfw.com reports,

A recent study indicates that temperature might play a more important role in sleep than light.
A story posted by the Wall Street Journal looked at a few studies that break down how temperature affects the body. They found sleep is most tightly regulated by temperature, not light, as the body's core temperature needs to drop to help initiate sleep.

One study suggests keeping the thermostat at 65 degrees is good for sleep. The National Sleep Foundation recommends temperatures between 60 and 67 degrees.

The studies also recommend taking a hot bath in the evening, as the body will cool down afterward and help drop the core body temp. A shower would not have the same effect.