I just tested mine, streaming Groove Salad at 128 kbps through iTunes... no heat or fan issues here. So it sounds like you might want to try doing an SMC reset:
1. Shut down your MBA properly.
2. On the keyboard, press and hold (simultaneously) the LEFT Control key, the LEFT Option key, and the LEFT Shift key. While holding these down with one hand (see if you can guess which one), use the other hand to hold down the POWER button for 6 seconds.
3. Once 6 seconds are up, release all keys/buttons.
Your MBA should now start, with a reset SMC. See if the heat and fans problem still occurs.