In the fall, I put my two potted hibiscus in my greenhouse and unfortunately forgot about them. About 10 days later, I remembered them and of course we had some beautiful warm days when the green house likely went over 100 degrees, because I did not have the fan and thermostat activated, because it was supposed to be winter, which is why I put them there to avoid frost. My plants had brown leaves and I thought they were both dead. However, I decided to water them anyway, just in case they were still alive and behold new leaves appeared.
These are tough plants.