Lack of oxygen?

Today, I was so unproductive at work today...there was no air ciculation. The A/C stopped working in our area, it was like walking into a air tight vault. At first I thought it was bearable, but then I was feeling worse. I must have drank at least six glasses of ice cold water during the afternoon alone and ice cream. It was at the point where my face became flushed as I was told by my coworker, couldn't concentrate and kept passing in and out of consciousness. Followed by a massive headache, dry eyes, it was horrible. It was almost like walking into an airtight vault, where the air has been sucked out. Couldn't go to the gym, afraid that I'd pass out...Although after sleeping for six hours with fresh air blowing through the room, I feel a bit better now. Thanks all!