With the immense popularity of the game of cricket in Sri Lanka, school level cricket is played competitively and socially by a large number of participants. As in many other sports, musculoskeletal injuries are a common occurrence in cricket. Exposure to hot and humid environments in Sri Lankan conditions during outdoor cricket play can also pose a risk for junior cricketers. To date, there has been no attempt to examine injury or illness among Sri Lankan junior cricketers, which hinders opportunities for injury prevention. The first aim of this thesis was to examine musculoskeletal injuries with a view to identifying injury incidence and associated risks during competitions. Specific injuries among different groups of cricketers were identified including 46.0% in fielders, 25.4% in bowlers and 20.3% in batters. Injury risk perceptions of junior cricketers recognised that these injuries were common, and highlighted the role of coaches and school cricket teachers in supporting junior cricketers. The second aim of the thesis was to study the potential impact of exertional heat illnesses (EHI) during cricket play. A considerable variation in heat stress risk parameters (climate, duration, and intensity of play) were observed among cricketers during test-cricket play. Study of risk perceptions related to EHI showed the importance of understanding EHI risks such as humidity and use of helmets. The results of this PhD have been provided to Sri Lankan Cricket and school cricket authorities with recommendation to develop and implement injury preventive measures such as use of helmets during batting to minimise the high number of match-time-loss facial injuries, and educating junior cricketers in modifying their perceived risk attitudes and beliefs related to musculoskeletal and EHI risks. Overall, this PhD has met the aim of completing the first large-scale scientific contribution towards promoting safety and preventing injuries among Sri Lankan junior cricketers.