Hibiscus

Hibiscus sometimes react that way to heat. I don't mean warm weather. A stone or masonry wall will store and reflect heat onto nearby plants even after the sun goes down. White stone/gravel walkways or ground cover will add to the heat. Windows of course reflect light and heat onto nearby plants. The petals on hibiscus blooms are actually thicker than the leaves, and therefore hold enough water to withstand heat that the leaves may not tolerate.