Does a scope need to warm up?

Here's a question for those thermal dynamics experts among us . . .

We all know about the need to allow a warm scope to cool down to the outside temperature before use, but what about the reverse? Does a scope need to "warm up" going from our cool and comfortable air conditioned homes to a warm and humid backyard? What is the effect on images of a cooler than ambient temperature scope versus a warm scope?

I agree with Chris -- instant dew formation when the
cold scope hits warm humid outside air is the
biggest problem.

Reflectors won't be bothered to much I guess -- cool
air sinks -- so there won't be heat plumes from the
mirror running up the tube.

Refractors will tend to run under-corrected while
cooling down, and in fact some are made over-corrected
to compensate for this. So if they are instead
warming-up, they might be a tad overcorrected.

Probably best to keep the scope somewhere not
fully air-conditioned, and start with the scope
near or slightly above outside temp.

Disregarding potential dew for the moment...

A temperature gradient -- be it descending (cooling) or ascending (warming) -- is still a gradient. Both scenarios promote turbulence and *can* affect local seeing.

Back to dew...

If the local "dewpoint" is lower than the temperature of your scope &/or its components, dew won't form. Warmer, more-humid locales are indeed more likely to promote scope dewing, if that scope is "warming up" outside. Drier climes don't have the same "warm-up dew" potential, but it's still a night-to-night consideration.

Best wishes.
-Dan