If you suspect that your pipes are frozen you can try to thaw the area out yourself. DO NOT attempt to use a torch with an open flame. The house could catch on fire or you could overheat a single spot and cause the pipe to burst. The best tool for a homeowner to use is a hair dryer on a low setting. Wave the warm air back and forth along the pipe so as not to overheat a single area. You might also try wrapping the pipes with rags and dousing them with hot water. This approach is a bit messy but effective. Be aware that the pipe may already be broken and the leak is not visible because the water is frozen. Be prepared to shut off the master valve!
For more information on residential water use and home leak detection download this brochure published by the American Water Works Association.