however, with improved care, it is no longer very accurate. the score is determined by adding the size of the burn (% tbsa) to the age of the person and taking that to be more or less equal to the risk of death. burns in 2013 resulted in 1.2 million years lived with disability and 12.3 million disability adjusted life years. complications a number of complications may occur, with infections being the most common. in order of frequency, potential complications include: pneumonia, cellulitis, urinary tract infections and respiratory failure. risk factors for infection include: burns of more than 30% tbsa, full-thickness burns, extremes of age (young or old), or burns involving the legs or perineum. pneumonia occurs particularly commonly in those with inhalation injuries. anemia secondary to full thickness burns of greater than 10% tbsa is common. electrical burns may lead to compartment syndrome or rhabdomyolysis due to muscle breakdown. blood clotting in the veins of the legs is estimated to occur in 6 to 25% of people. the hypermetabolic state that may persist for years after a major burn can result in a decrease in bone density and a loss of muscle mass. keloids may form subsequent to a burn, particularly in those who are young and dark skinned. following a burn, children may have significant psychological trauma and experience post-traumatic stress disorder. scarring may also result in a disturbance in body image. to treat hypertrophic scars (raised, tense, stiff and itchy scars) and limit their effect on physical function and everyday activities, silicone sheeting and compression garments are recommended. in the developing world, significant burns may result in social isolation, extreme poverty and child abandonment. epidemiology disability-adjusted life years for fires per 100,000 inhabitants in 2004. no data < 50 50–100 100–150 150–200 200–250 250–300 300–350 350–400 400–450 450–500 500–600 > 600 in 2015 fire and heat resulted in 67 million injuries. this resulted in about 2.9 million hospitalizations and 238,000 dying. this is down from 300,000 deaths in 1990. this makes it the fourth leading cause of injuries after motor vehicle collisions, falls, and violence. about 90% of burns occur in the developing world. this has been attributed partly to overcrowding and an unsafe cooking situation. overall, nearly 60% of fatal burns occur in southeast asia with a rate of 11.6 per 100,000. the number of fatal burns has changed from 280,000 in 1990 to 176,000 in 2015. in the developed world, adult males have twice the mortality as females from burns. this is most probably due to their higher risk occupations and greater risk-taking activities. in many countries in the developing world, however, females have twice the risk of males. this is often related to accidents in the kitchen or domestic violence. in children, deaths from burns occur at more than ten times the rate in the developing than the developed world. overall, in children it is one of the top fifteen leading causes of death. from the 1980s to 2004, many countries have seen both a decrease in the rates of fatal burns and in burns generally. developed countries an estimated 500,000 burn injuries receive medical treatment yearly in the united states. they resulted in about 3,300 deaths in 2008. most burns (70%) and deaths from burns occur in males. the highest incidence of fire burns occurs in those 18–35 years old, while the highest incidence of scalds occurs in children less than five years old and adults over 65. electrical burns result in about 1,000 deaths per year. lightning results in the death of about 60 people a year. in europe, intentional burns occur most commonly in middle aged men. developing countries in india, about 700,000 to 800,000 people per year sustain significant burns, though very few are looked after in specialist burn units. the highest rates occur in women 16–35 years of age. part of this high rate is related to unsafe kitchens and loose-fitting clothing typical to india. it is estimated that one-third of all burns in india are due to clothing catching fire from open flames. intentional burns are also a common cause and occur at high rates in young women, secondary to domestic violence and self-harm. history guillaume dupuytren (1777–1835), who developed the degree classification of burns cave paintings from more than 3,500 years ago document burns and their management. the earliest egyptian records on treating burns describes dressings prepared with milk from mothers of baby boys, and the 1500 bce edwin smith papyrus describes treatments using honey and the salve of resin. many other treatments have been used over the ages, including the use of tea leaves by the chinese documented to 600 bce, pig fat and vinegar by hippocrates documented to 400 bce, and wine and myrrh by celsus documented to 100 ce. french barber-surgeon ambroise paré was the first to describe different degrees of burns in the 1500s. guillaume dupuytren expanded these degrees into six different severities in 1832. the first hospital to treat burns opened in 1843 in london, england, and the development of modern burn care began in the late 1800s and early 1900s. during world war i, henry d. dakin and alexis carrel developed standards for the cleaning and disinfecting of burns and wounds using sodium hypochlorite solutions, which significantly reduced mortality. in the 1940s, the importance of early excision and skin grafting was acknowledged, and around the same time, fluid resuscitation and formulas to guide it were developed. in the 1970s, researchers demonstrated the significance of the hypermetabolic state that follows large burns.