How can I optimize my sleep using the temperature minimum?

Use your temperature minimum—the time your body temperature is lowest, usually 90 minutes to two hours before your average wake time—as a reference for shifting your sleep schedule. For example, if you usually wake at 7 a.m., your minimum is roughly 5 a.m. 1

• 1. Bright light or exercise: To shift your clock earlier, get bright light and/or exercise in the hours after your temperature minimum. To shift it later, use bright light or exercise four to six hours before the minimum. 2 3
• 2. Cool bedroom: Keep the sleeping environment relatively cool; the discussion recommends lowering it by at least three degrees, while using blankets as needed. The guidance does not specify a target of 67°F. 4
• 3. Warm bath before bed: A hot bath or sauna for no more than 20–30 minutes, followed by getting out and cooling off, can produce a compensatory drop in core temperature and make it easier to fall asleep. 5

In short, use the minimum to time cues that advance or delay your clock, and use evening cooling to support sleep.