(JTA) — Since Feb. 24, when Russian troops invaded Ukraine, Jewish groups from around the world have flooded the country with support, from food to medical care to evacuations.

Now, as temperatures fall and Russian attacks on Ukraine’s power grid ramp up, those groups are directing their efforts toward making sure that Ukrainian Jews can remain warm and safe in the coming months.

A Ukraine response group organized by the Orthodox Chabad-Lubavitch movement, whose rabbis are the Jewish leaders in many Ukrainian cities, is raising funds to buy hundreds of generators to equip each its sites...