A study conducted by the George Institute for Global Health showed that cold weather increases the risk of cerebral hemorrhage, the most dangerous of all forms of stroke. Also, brain hemorrhage is more likely to occur within two to three hours of exposure to cold weather. The results were recently published in the prestigious academic journal Public Library of Science. According to the report, the study is the first in the world to correlate hour-by-hour temperature with cerebral hemorrhage. The study, which examined 1,997 brain hemorrhage patients worldwide (1,191 from China) between 2008 and 2012, found that about 80 percent of strokes occurred in environments below 20 degrees Celsius. Also, brain hemorrhage was more likely to occur within 2 to 3 hours of human exposure to cold weather. The study also found that compared with the optimal temperature of 20 degrees Celsius, the incidence of cerebral hemorrhage increased by 137% when the temperature dropped to 10 degrees Celsius; at zero degrees Celsius, the incidence of cerebral hemorrhage increased by 192%; at minus 10 degrees Celsius, it climbed to 313%; and at minus 20 degrees Celsius, it was 576%. The study provides evidence that increased blood pressure may be a potential factor in brain hemorrhage. Patient data came from 144 hospitals in 21 countries, including the United Kingdom, Australia, India, Pakistan, the United States and China. The 16 cities in China that participated in the study included a number of northern cities, such as Changchun, Beijing, Tangshan and Shijiazhuang. Data from China show that the cold northeastern region has the highest incidence of stroke at 486 per 100,000 people per year, while the warm southern region has 136 per 100,000 people per year. Lead author of the article, Dany Cheng of the George Institute for Global Health, describes the findings as revealing potential needs and opportunities for public health interventions, such as installing central heating systems in cold regions, raising public awareness, and providing advice and warnings to high-risk populations. Established in Australia in 1999 as a not-for-profit medical research institute affiliated with the University of Sydney, the George Institute for Global Health now has offices in China, India and the United Kingdom, with affiliations with Peking University Medical School, the University of Hyderabad and the University of Oxford, respectively.