either too hot or overfertilized.. I would say a mix of both... Some plants hate high temps and alot of nutes. I would get a fan in there to give it some airflow as well as a thermometer/hygrometer with a sensor to monitor the max/min temps. I would give it just pure clean water and water it about 1/4 gallon(or less depending on potsize) 3 times a day for about 3 days then start back about 1/2 strenght of your nutrients.