Get the blankets and the freeze cloths ready. The valley is expected to come under by a "hard freeze" overnight, with temperatures dipping into the 20s in the outskirts of Phoenix.
But if you think covering your plants and pipes is a lot of work, imagine being in charge of protecting an entire citrus grove.
You cannot put a cloth over an orange tree, so people in the citrus business have to try other things to keep the severe cold away from their crop.
It's going to be no small feat to protect the trees 20,000 citrus trees planted on 200 acres at Citrus Heights Farms at Greenfield and McKellips in Mesa.
It is home to some of the best oranges in the United States.
"It is a Seville navel and it is good quality, in our opinion the best navel orange in the country," says Todd Shell of Citrus Heights Farms.
But now those oranges are in peril. A cold snap can destroy the crop in a matter of hours.
"You know, if it gets below 28 for a few hours the fruit is in jeopardy," says Shell.
Now, citrus farmers are doing everything possible to keep the trees warm enough to survive. One of the most important things: put a lot of water around the trees.
"Running the water. It is warmer than the air, creates heat and the heat rises up through the trees."
Farmers also use wind machines and may even hire a helicopter to move around the slightly heated air rising from the water.
Right now, they're just hoping it stays just warm enough outside for the crop to survive. It's a scary time, during a year that's been looking like an outstanding crop.
"Actually for the amount of fruit on the trees it is good, the last few years not good, and now a good harvest and we have the chance of losing it all," says Shell.
Every degree counts -- here's hoping the orange groves make it through this cold snap without serious damage.
Speaking of saving crops, residents are reminded to protect and cover their vulnerable plants overnight.