Meanings of feel the tautness in English

The vehicle was cramped and claustrophobic, but he was glad to feel the tautness of his suit relaxing.

The burned skin on his calf was still contracting, too; he could feel the tautness of the scalded area pulling at the skin around it.

Two receivers clicked and Kenny, remembering that he could not definitely locate Joan until six, felt the tautness of his control slip dangerously.