A boil is a skin infection that begins in a hair follicle or oil gland, states WebMD. Boils are typically caused by staphylococcal bacteria, and the buttocks are one of the most common places a boil occurs. Normally, the bacteria enter the body through a tiny cut.
If a fever is present, the area around the boil is red, or red streaks appear, medical attention is required, states WebMD. Further indications of a serious infection include appearance of a second boil, severe pain, or failure of the boil to drain. A person with diabetes, a heart murmur, or any issue with his immune system should seek medical attention for a boil promptly. Most often, boils do not need immediate medical attention. If high fever and chills develop, emergency medical services are needed.