Summer heat extremes are among the major meteorological disasters in China, posing severe threats to public health, economic and social development, and natural ecosystems. To address the nation's urgent need for managing heat-related disaster risks, we independently developed a prediction model system for summer heat extremes in China, based on new scientific insights. Since 2018, the model system has demonstrated stable and reliable predictive capabilities, relatively accurately capturing the spatial patterns and anomalies of summer heat extremes. In May 2025, using this system, we predicted that the number of summer hot days in 2024 would be 12.55 days, which is 2.69 days more than the average of normal years (1991-2020). The forecast also indicated more severe heat extremes, elevated disaster risks, and pronounced regional differences. The most significant above-normal heat extremes were expected in the middle and lower reaches of the Yangtze River Basin, South China, the Sichuan Basin, southern Xinjiang, northern Jiangsu, and northern Anhui. These were followed by the Beijing-Tianjin Plain, Shandong, Henan, southern Shaanxi, parts of northeastern China, parts of Gansu, and northern Ningxia. Based on these findings, we also provide response recommendations to prevent and mitigate the impacts of summer heat extremes across China.