A Lizard Photography

On a certain day, I sat outside reading news from my device. The sun was very hot then but I sat under a shadow.

As I was there, a male lizard ran to my front and opened its mouth. I was wondering what it was up to. It kept opening its mouth as though it swallowed that wasn't okay with its system.

It later turned its face towards another direction before running to a base to stand and still observing. I noticed it continued that act. I wonder what actually was wrong with it.