Definitely, NOT! Seedlings require a constant temperature of near 70úF..24 C.....To subject them to such low temperatures even for short periods would spell doom to them.
Later, as the seedlings mature into larger plants they can be acclimatized to outside temperatures by giving them daylight sunlight, back into the warmth, then back outside each time giving more extended time.

We can assume you have thinned the seedlings, and they have gained their second set of leaves.

Thank you. I am new at this. They are about 6-8 inches tall and blooming. I will harden them off as it warms up. I am glad I asked. I would hate to have killed them.