World Jewish Relief refugee crisis programmes manager Keren Simons said: "The new project we will be supporting is an initial reception at entry points, including first aid tent, warm clothes, hypothermic blankets, water and food for all those people coming off boats.
"There hasn't been a medical tent there until recently, so people coming off the boat with hypothermia or illnesses were not getting the help they need.
"This is a mobile unit with real expertise in the team, and has the flexibility to move around when things change, as they do so often at the moment."
On visiting the Greek island where up to 3,000 refugees have been arriving each day, Rabbi Wittenberg said: "I have been very moved to see at first hand the work of Praxis, one of World Jewish Relief's partners in Greece.
"I am impressed by how many people care and how much they are giving of themselves and their skills.
"Only two or three busses arrived while I was there. But I watched the people – young and old, families with children among them – with pain.
"They had crossed the water safely, but who knows what they had gone through before that, and what stories of lost homelands they will bequeath to their children."
He said: "I am keen to support this work in any way I can and I intend to speak about what I have seen, to try and engage others in this important work."