One of the most dangerous aspects of a burn is the risk of a secondary infection that comes with the burn. Burns not only remove skin, which acts as a protective layer to keep out bacteria, but burns also limit the pathways used by the body to transport antibacterial substances to the injured area.
One of the biggest difficulties in determining if a burn has become infected is that the burn itself will produce many symptoms that normally indicate an infection. Most burns will produce a slight fever. The difference between a burn and an infection is the severity of the fever, and also when it is present. In most cases the fever from the burn will be less than 100 degrees, and will occur in the first 24 hours and then gradually subside. If the burn becomes infected, the fever will continue to rise above 100 degress and last past the initial 24 hours following the burn.
Another sign of a burn and infection is redness around the site of the burn. Immediately after a burn, the injured tissue will obviously display redness, but the area surrounding the burn will also turn red as the waste materials from the dead cells ultimately kill the cells in the tissue immediately around the burn. This will occur in the first 24 hours, and it is not unusual for large areas around the original burn to become dicolored. This area, however, should shrink rather rapidly after the 24 hours. But if the burn has become infected, the red area around the burn will continue to expand well past the initial 24 hours. If this is a small burn that you don´t feel requires immediate medical attention, it is still wise to use a pen to draw marks at the outer boundary of the reddened area just o be sure that it is not expanding.