What crucial pre-observation step helps prevent condensation on optics when moving a telescope into cold air?

Answer

Placing the optical tube assembly outside at least an hour before use to reach thermal equilibrium.

Telescopes need time to acclimate to the outside temperature; rushing this process causes a temperature differential that can lead to rapid dew or frost formation on the optics.

What crucial pre-observation step helps prevent condensation on optics when moving a telescope into cold air?
weatherobservationskystargazingcondition