Name: Will Creed NYC Prof. plant consultant & educator
The symptoms on that leaf are generic, meaning it can have multiple causes. The heat could be the problem, but it would be best if you posted a photo that shows the entire plant and provided more info about its environment.
Will Creed
Horticultural Help, NYC
www.HorticulturalHelp.com
Contact me directly at [email protected]
I now have a book available on indoor plant care