Young men and women are doing charitable work; is it permissible for them to meet in order to organise the work?
Question

A group of young people of both sexes are doing charity work, such as visiting orphans and the sick and feeding the poor and so on. They are interacting directly within the limits of organising the charitable work. Is it permissible for them to meet together to do this work?.
Praise be to Allah.Doing charitable work, such as visiting orphans and the sick and feeding the poor, is an important matter that is promoted and encouraged in Islam and brings a great deal of reward. Allaah says (interpretation of meaning):
“And they give food, in spite of their love for it (or for the love of Him), to the Miskeen (the poor), the orphan, and the captive,
9. (Saying): ‘We feed you seeking Allaah’s Countenance only. We wish for no reward, nor thanks from you.
10. ‘Verily, We fear from our Lord a Day, hard and distressful, that will make the faces look horrible (from extreme dislike to it).’
11. So Allaah saved them from the evil of that Day, and gave them Nadhrah (a light of beauty) and joy.
12. And their recompense shall be Paradise, and silken garments, because they were patient”
[al-Insaan 76:8-12]
and the Prophet (blessings and peace of Allaah be upon him) said: “I and the one who sponsors an orphan will be like this in Paradise,” and he gestured with his forefinger and middle finger, holding them slightly apart. Narrated by al-Bukhaari (5304) and Muslim (2983). 
Ahmad narrated (7260) from Abu Hurayrah (may Allaah be pleased with him) that a man complained to the Messenger of Allaah (blessings and peace of Allaah be upon him) of his hardheartedness, and he said to him: “If you want to soften your heart, then feed the poor and pat the head of the orphan.” this hadeeth was classed as hasan by al-Haafiz in al-Fath (11/151) and by al-Albaani in Saheeh al-Jaami‘ no. 1410. 
Muslim (2568) narrated from Thawbaan (may Allaah be pleased with him) that the Messenger of Allaah (blessings and peace of Allaah be upon him) said: “Whoever visits a sick person will remain in an orchard of Paradise.” It was said: O Messenger of Allaah, what is an orchard of Paradise? He said: “The reward is Paradise and its fruits.” al-Nawawi said: i.e., that will bring him to Paradise where he will harvest its fruits. 
Al-Tirmidhi (969) narrated that ‘Ali (may Allaah be pleased with him) said: I heard the Messenger of Allaah (blessings and peace of Allaah be upon him) say: “There is no Muslim who visits a (sick) Muslim in the morning, but seventy thousand angels will send blessings upon him until the evening comes, and if he visits him in the evening, seventy thousand angels will send blessings upon him until morning comes, and he will have a garden in Paradise.” Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi. 
And there are other well-known texts which speak of the virtue of these actions. 
There is nothing wrong with a woman doing these actions, treating orphans kindly, feeding the poor, and visiting sick women, so long as she adheres to that which Allaah has commanded of hijab, covering and not mixing with men. Indeed this is mustahabb and recommended for her. 
Undoubtedly women have a great role to play in this field, because they are able to get to know about poor families and convey help to them, and cooperate with their Muslim sisters and encourage them to spend and give in this field. But that is no justification for them to meet with non-mahram men on the grounds of organising or doing charitable work. Rather it is sufficient for them to work with other women like them, and for men to work with men, so as to block the means that may lead to haraam and to prevent any fitnah occurring because of them or to them. 
If the matter requires cooperation of men with women in this field, then it should be done with the wives of these men or some of them, who can get in touch with the women and organise the work with them. 
If these young men are not married, then the fitnah in this case is greater, and the danger is greater, and it is one of the footsteps of the Shaytaan which Allaah has warned us against, as He says (interpretation of the meaning): 
“O you who believe! Follow not the footsteps of Shaytaan (Satan). And whosoever follows the footsteps of Shaytaan (Satan), then, verily, he commands Al‑Fahsha’ [i.e. to commit indecency (illegal sexual intercourse)], and Al‑Munkar [disbelief and polytheism (i.e. to do evil and wicked deeds; and to speak or to do what is forbidden in Islam)]. And had it not been for the Grace of Allaah and His Mercy on you, not one of you would ever have been pure from sins. But Allaah purifies (guides to Islam) whom He wills, and Allaah is All‑Hearer, All‑Knower”
[al-Noor 24:21]
Undoubtedly, young men meeting young women, or men meeting women, even on the grounds that it is for organising charity work, is one of the footsteps of the shaytaan, which may lead to that which is even worse. 
There are so many stories and tragedies which have occurred because of that. The wise person is the one who learns from others and does not become a lesson for others. 
These people have to fear Allaah, and not mix good deeds with bad deeds. They should keep away from the causes of fitnah and deviation, and be aware of the tricks and plots of the shaytaan. 
We ask Allaah to protect us all from fitnah in word and deed. 
And Allaah knows best.