Be careful turning the settings as cold as possible. We have been told by the maintainence staff that this can actually cause the fridges to ice up and stop cooling. They are not actual refrigerators since they don't have compressors in them. We have had them come to our room a few times because the previous guest turned the knob all the way.
For small items (like freezer packs) that need to be frozen, you may want to check with the bell stand. We were told they have a freezer that can be used for these items.