C (140°F) is perfectly appropriate. The key is not to make it a regular habit in order to preserve the fabric.
Small Steps That Make All the Difference
Temperature isn’t everything. For truly comfortable sheets night after night, a few simple habits can make all the difference. First, always turn your sheets inside out before washing them: this protects the colors and reduces visible wear. Next, avoid overloading the machine, so that the water and detergent can act properly on all the laundry.
In terms of frequency, washing once
