Originally Posted by Borrego Dave
My bedroom doesn't have condensation in the morning but the egg does.
condensation happens when moist air hits a surface that is at dew point temperature.
To prevent condensation under your mattress put a piece of Reflectix under it. That will reflect the body heat (and moisture) and the warm moist air then won't condense on the cold surface under the mattress. You will sleep warmer on cold nights. Obviously not needed when the temperature does not get as low as the dew point.