Make sure you can get a cross-breeze in your place if possible. That means opening up windows that are across from each other. If you want to buy something, get a fan that has the ability to circulate. I would also keep drinking cool drinks and wear loose clothing!
If your air conditioner is broken and you need to keep cool, try standing fans. They don't make the air any cooler, but it feels good to have the breeze blowing on your skin. If that doesn't work, find the nearest pool and jump in.