What is the ruling on male and female colleagues going out together on a recreational trip, knowing that the males are younger than the females?

Allah commanded believing men and believing women to lower their gaze, and commanded women to observe hijab (definition). The Prophet, peace and blessings be upon him, forbade a man from being in seclusion with a non-mahram (definition) woman, and prevented a man from entering upon women. He also forbade a man from shaking hands with a non-mahram woman, as a means of blocking the path to what is unlawful. There is no need for such trips, and it is unlikely that they would be free from harm. Therefore, avoid them to cut off the root of evil. Whoever is keen on the soundness of his heart and his religion should distance himself from working in places where men and women intermingle.