An air carrier flight returned to their departure airport after experiencing a loss of cabin pressurization.

Narrative

We noticed our ears popping; fog in the galley; and the temperature in the cabin was hot. Soon after the oxygen masks dropped and I pushed the emergency button on the interphone to inform the Captain. The Captain said we were going back to our departure airport and he would call me back. I then donned my oxygen mask while securing the galley. The Captain then called and informed us of a moderate level emergency with a normal landing planned in thirteen minutes with pressurization problems.Events were happening fast and I gave the announcement; secured the cabin; and checked passengers. They were all OK and masks were donned. I then put my oxygen mask on again. Captain called again and informed us he needed to burn some fuel before landing; advised how much time was left and asked if everything was OK. The Captain then told us we were below 10;000 FT and to advise the passengers they could take their masks off if they wanted to. I informed the passengers.Flight attendants continued to check the cabin. Captain did a great job of keeping us informed. Passengers thanked flight attendants for doing a good job.