Hi, Tracy!!! I suppose that your pepper plant is been under watered. Watering is very important during the maturation time: if you don't watered enough your plants, their fruits become more hot. For your next peppers coltivation, water more your plants during the maturation phase but pay attention, pepper roots are very susceptible at waterlogging. Do something to improve the conditions of soil drainage.!
I hope that Gtp can help us in peppers coltivation. :-)