Same here on the chilies. When we make poppers one may be cool and the next one HOT.If you look here on my chart http://freebeerforyorky.com/scoville.htm you will see a substantial variation in SHUs even in the same "type" of chili. Those that you have pictured look like red pepperocini to me - we only have green here. Even if you bite a chili raw (not recommended for the faint hearted) it's difficult to ascertain how much heat will be imparted to the dish. Even chilies from the same batch here may differ significantly in heat units.
Cool for lack of a better term.