Climate change leads to heat-related changes in labor productivity, which have additional economic impacts. Based on a framework that considers the impacts evolving from climate change to labor productivity to economic impact, we estimate the changes in labor productivity for indoor and outdoor activities and different work intensities at the grid level in China under a wide range of climatic and socioeconomic conditions and then evaluate the economic impacts in seven regions and eight sectors. The results show that (a) the negative impacts of labor productivity are concentrated in outdoor sectors, and the labor productivity of indoor sectors will decrease slightly or even increase due to high air-conditioning device penetration rates under relatively optimistic scenarios. (b) The national results show that total economic impacts increase by 0.28%-0.61% of the GDP for each 1 degrees C rise in the temperature, and the total economic impacts of labor productivity reductions in the most pessimistic scenario reach 1.15%-2.67% of the GDP in 2100. (c) The regional results indicate that the regions with lower labor productivity impacts (Northwest and Northeast China) still suffer large economic impacts, highlighting the importance of economic impact assessments across the regions. (b) The sectors in the seven regions of China that are most sensitive to climate change are agriculture and construction. The economic impacts in the manufacturing and service sectors, which contribute 22%-35% and 11%-15% of regional GDP losses, respectively, cannot be ignored, and should receive more attention in climate mitigation policies. Plain Language Summary Climate change will increase the heat stress in working environment, which limits the labor productivity of workers. Reductions in labor productivity will also lead to economic impacts. The consequences of this impact chain within China have been evaluated for the first time. Outdoor workers will be seriously affected by heat stress, while indoor workers' productivity may benefit from the popularity of air-conditioning devices. However, all regions of China will face the negative economic impacts of increased heat stress under climate change. Even if the heat-related labor productivity of a region is not severely affected, the economic impacts cannot be ignored due to the economic links between regions and sectors. The agriculture and construction suffer from the most serious economic impact. Although labor productivity in the indoor sectors will benefit from the popularity of air-conditioning devices, the economic impact of the manufacturing and service sectors cannot be underestimated.