Question
I live in the coastal bend of South Texas and have a 60 gallon above ground water garden with 8 goldfish.  The temperature will be in the high 30's in a few days.  Will my goldfish be okay or to I need to purchase a heater?

Answer
They will be fine as far as temperature goes.  Goldfish can live in water down to freezing as long as it doesn't actually freeze them or freeze all of the surface preventing gas exchange.  I hope your goldfish are small because 8 adult goldfish should have at least 200 gallons or so.  I have a page on pond winterization but compared to us with real winters, where you live is warm!  
http://www.fishpondinfo.com/winter.htm

Good luck!
Robyn