I'm waiting for my sister to finish her shower so I can wash my face. The problem is that it's her day off today so the shower can take a long time (I'm now waiting for over 15 minutes). Using cold water isn't a problem, water pressure only goes down a little bit, so I've brushed my teeth. However, using warm water will diminish the shower jet to a trickle, and I'm not planning to wash my face with cold water since it isn't exactly warm.
Maybe I'm just too nice and I should just use warm water; everybody else seems to use warm water when I'm taking a shower.