Well, let's eliminate the other possibilities... how frequently were you watering? If anything, it sounds as if it was too much water rather than not enough, or (as I've suggested) over-feeding. Was your soil nice and airy? Did the roots smell funky when you pulled them out of the soil? If the soil smelled rancid, then the chances are the roots were suffocated by either too much water or not enough aeration in the soil (the soil was too compact). Did you make your own soil or did you use a store bought mixture? Was there perlite in it? How frequently were you feeding? What was the daytime temp in your room? It seems extremely unlikely that you killed them with heat, unless it was truly hot in your room (like in the 90's, maybe)... they are pretty resilient little plants, and can handle quite a range of extremes.
The more I think about it, the more I'm thinking it almost must have been too much fertilizer... was the plant rootbound when you pulled it from the pot? If so, it is extremely difficult to over-water at this point (unless you are literally watering every day, and the soil is waaaay too compacted). We'll get to the bottom of this murder (I mean accident)...
The more I think about it, the more I'm thinking it almost must have been too much fertilizer... was the plant rootbound when you pulled it from the pot? If so, it is extremely difficult to over-water at this point (unless you are literally watering every day, and the soil is waaaay too compacted). We'll get to the bottom of this murder (I mean accident)...