A 19-year-old Long Island woman was arrested Sunday for leaving a toddler she was babysitting in a scalding hot bath that burned 20 percent of the child’s body, according to Nassau County police.

Yenci Elizabeth Lopez of Hempstead allegedly plunged the 2-year-old boy into blistering-hot water at around 6:30 p.m. Sunday and left him there for several minutes, despite the child screaming in pain, police said.

Lopez then left the house without seeking medical attention for the boy, who suffered second-degree burns, cops said.

The child was taken to a local hospital, where he was treated in the burn unit, cops said.

Lopez faces a number of charges including reckless assault of a child and endangering the welfare of a child. She is expected to be arraigned Monday.