Any temp of water will work. And rather than using a collander, put the rice in a bowl and fill the bowl with water. Then slosh the rice around a bit. Any grains that have the outside cover still on them (the tough outer coating) will rise to the top and you can remove them before cooking. If you don't remove them ahead of time, you might be unpleasantly surprised with a hard crunch when you eat it, because the hard cover doesn't soften with cooking, and it's like biting into a pice of stone.