If you have an older model slow cooker or you purchase one used at a garage sale, you should make sure you test it to ensure that it will raise the temperature to a high enough degree that will kill harmful bacteria in meat such as beef and chicken. Fortunately, it is quite easy to test your crock pot to make sure it will cook your meals safely.
To test to ensure your slow cooker is getting hot enough to safely cook your meals, fill the slow cooker with two quarts of water. Place the lid on and heat for eight hours. After eight hours, lift the lid and immediately place a thermometer into the water. It should read 185F.
If it reads higher than 185F, you should adjust your cooking time slightly. This will ensure your meals are not overcooked.
If the water does not read 185F you need to discard the slow cooker, or exchange it if you have recently purchased it new or it is under warranty. If you use a slow cooker that does not reach 185F after eight hours, you risk getting sick because it is not reaching the safe cooking temperature which is required for meat.