The study identified and biochemically characterized four Rubisco activase (Rca) isoforms in cowpea (Vigna unguiculata) and evaluated their performance during a simulated 5‑day heatwave (+10 °C). Rca10 and its beta variant displayed superior thermal stability, broader optimal temperature range, and enhanced ATP‑hydrolysis and Rubisco reactivation rates, suggesting they could be leveraged to improve cowpea thermotolerance under future climate extremes.