"warm rocks" is correct and usable in written English.
You can use it to describe a warm surface such as a heated stone path. For example: "We walked along the heated stone path, feeling the warmth of the warm rocks beneath our feet."
We had gone for a swim that morning, and were thawing out on the warm rocks and talking about automation.
Then he puts warm rocks in my palms and under my shoulders, rubs my back with a hot rock.
Ms. Wetterau stuck warm rocks in my hands, wrapped me in a cocoon of blankets and promised the heat of the stones would penetrate deep into tight muscles, loosen them and relieve stress.
On the shore a couple embraced and when the woman moved away the man was as erect as a satyr as he stood on the warm rocks.
However, on sunny days, you might find rattlesnakes warming themselves on warm rocks or asphalt.
Later in the night, Dent May delivered a set of sparkling, warm rock.
The warm rock allowed us to discard several layers of clothing before resting our backs on the wall and tipping our faces upward.
Also topnotch were the warm rock shrimp, a dozen or more, served with sauteed rings of red onion and crisp spinach.
As the days passed, the river water grew clean and sweet, and the warm rock pools filled with water for baths and washing.
The images do at last reveal areas of warm rock emanating from the lower mantle far beneath Hawaii and other Pacific hot spots, but the columns are far larger in diameter than previously envisioned: these rare birds have stocky legs nearly five hundred miles wide.
Helium-3, the lighter isotope and a signature of black smokers, was scarce in the plume, given the amount of missing magnesium, leading the researchers to estimate that up to 10 times more chemical processing takes place in the warm rock within 2 to 10 kilometers of the central ridge axis than at the ridge axis itself.
