Many people report heat wakeups between 2 a.m. and 5 a.m. because REM periods become longer in the second half of the night, when thermoregulation dynamics change and bedding heat buildup has already accumulated.
The practical fix is reducing cumulative heat and humidity load before REM-heavy windows. Start with moisture-wicking layers, humidity control, comforter selection strategy, and pillow setup strategy.
For direct product guidance, review best cooling comforters and best cooling pillows, then confirm durability with washing guidance.
System-level planning still matters most, so finish with building a cool bed.