DECLARE @updated_Rows INT;
SET @updated_Rows = 1;
WHILE (@updated_Rows > 0)
BEGIN
UPDATE top(10000) XXX SET XXX.YYY = #TempTable.ZZZ FROM XXX
INNER JOIN #TempTable ON XXX.SomeId=#TempTable.SomeId
WHERE SomeConditions
SET @updated_Rows = @@ROWCOUNT;
END