Plumbing in Phoenix fails from heat, scale, and slabs more than from freeze. The rare cold night is not the design condition. The design condition is a water heater in a garage that bakes, supply lines in an attic that cooks, and hard water that leaves mineral behind in every tank and valve. A pinhole overhead becomes a ceiling flood that looks like a roof problem until someone finds the line. A warm stripe in the tile can be a slab leak. Irrigation and pool fill lines confuse the picture if you do not separate them from the house water.
Find the main shutoff before the day you need it. On the call, say whether you already closed it. Say whether the leak is supply or drain, and whether it is at a single fixture. A tub that drains slowly is not a water heater that is leaking at the pan. Several fixtures backing up together point at a branch or the building sewer, and palo verde or mesquite roots in older citrus neighborhoods are a familiar reason. Ask whether the work is a cable only or a repair of the pipe, and whether a camera is included if the cable does not hold.
On a heater, say gas or electric and tank or tankless if you know. Ask whether the scope includes a shutoff, a pan, a discharge line, haul-away, and a look at the flue. Scale is often why the tank is noisy or empty of hot water. Softeners are common and sometimes they are the thing that failed, with a hose running when it should not. Evaporative cooler supply lines on older houses add another leak at the roof. Manufactured homes and block houses do not hide their fittings in the same places. Say which you have.
Do not wait on a supply leak to see if it stays small. Attic lines in this heat do not become kinder overnight. Call the number on this page.