In my opinion, slow cooker fiesta chicken isn't spicy per se but it does have a ton of flavor! What I love about this recipe is that you can really control the amount of heat the finished chicken dish has. For example: -Rather than fiesta ranch seasoning mix, use spicy ranch seasoning. -Use mild, medium, or hot salsa depending on what your goal is. -Diced canned green chiles also are sold in mild, medium, and spicy versions. Plus there is also fire-roasted which usually implies more spiciness.  -Add extra chili powder to spice this Crock-Pot fiesta chicken up somewhat. -For a much spicier recipe, add a few shakes of cayenne pepper!