Mr. Hernandez was the husband of Lucille Hernandez, a clinic patient in the Season 1 episode Heavy. He was portrayed by actor Ramon Franco.
Lucille had been diagnosed with a huge benign tumor. However, she refused surgery to remove it because she thought the doctors were trying to make her skinnier.
When Mr. Hernandez learned of this, he asked Gregory House to speak to her again to convince her to have the surgery. House wasn't interested and told Mr. Hernandez that the tumor probably wasn't harmful. He also learned that Mr. Hernandez liked the fact his wife was heavy and thought she could re-gain the weight if she wanted. However, he was more concerned about her health. House tried to walk away but Mr. Hernandez showed him pictures of their six kids and House realized that several of the kids weren't fathered by Mr. Hernandez and he realized why Lucille refused the surgery.
House confronted Lucille with her infidelity and realized she was avoiding the scars that went with the surgery because although her husband didn't care about them, her other lovers might. He reassured her that she could find other lovers who were actually excited by her scars and she agreed to the surgery.