It is a common complication after deep burns. It can be a single bacteria or mixed infection of multiple bacteria, and occasionally caused by fungi. Generally, it is mostly a single bacteria in the early stage, and mixed infection in the late stage. It often occurs within 2 weeks after the burn, and the earliest occurs on the second day. It is less likely to occur after the granulation of the wound. Common pathogens are Staphylococcus aureus, Pseudomonas aeruginosa, Proteus and Escherichia coli. The clinical manifestations are generally sepsis, which can be high fever (above 42°C) or low temperature (below 36°C), mostly remittent fever. After sepsis occurs, the original post-burn tachycardia is more significant, and toxic myocarditis, toxic hepatitis, shock, etc. may occur. Paralytic tympanitis is also a common symptom, which may be accompanied by changes in consciousness. The wound surface may deteriorate in a short time, with a dark color, increased necrotic tissue and secretions, and easy bleeding.