What did Superman do to Lois to fix her fatal wound?

Question

In Man of Steel movie, Lois followed Superman to thousands years old alien ship where she was wounded by security bot. Then, Superman did something with his heat vision to save her. What was that?

Answer 1

Superman uses his heat vision to cauterize her bleeding injury. Since he has the ability to use his "x-ray" vision or enhanced visual senses to see the full extent of her injuries, it was relatively easy for him to stop the wound from bleeding.

• The medical practice or technique of cauterization is the burning of part of a body to remove or close off a part of it in a process called cautery, which destroys some tissue, in an attempt to mitigate damage, remove an undesired growth, or minimize other potential medical harmful possibilities such as infections, when antibiotics are not available.

• This is not a standard trope for Superman preferring to allow medical professionals to do their job, but as an emergency measure, it was probably as good as any surgeon's basic field work.

• This was a reversal on the standard trope of Lois Lane NOT knowing who Superman is, she instead is fully aware since she followed Clark onto the alien vessel and he makes no effort to hid his abilities.

Answer 2

The film's official novelisation gives a slightly more clear view of the events. He used his x-ray eyes to examine her wound, then used his laser-vision to cauterise the wound internally to prevent her from bleeding internally.

“You’re hemorrhaging internally,” he said. “If I don’t cauterize the bleed, you’ll die.”
She didn’t understand. “How—?”
“I can do things other people can’t,” he said simply. His fingers found hers, squeezing gently. “Hold my hand. This is going to hurt.”
His eyes glowed like burning coals. Ruby beams shot from his pupils to penetrate her ribcage just above her liver. Lois cried out in pain. Her mysterious benefactor was right about one thing.
It did hurt... a lot.
The procedure was over in a second, though. His eyes dimmed back to normal. Shock caught up, though, and she felt herself passing out. The last thing she saw, before everything went dark, was him smiling down at her, like she was going to be okay.