Human pose estimation has applications in numerous fields, including action recognition, human-robot interaction, motion capture, augmented reality, sports analytics, and healthcare. Many datasets and deep learning models are available for human pose estimation within the visible domain. However, challenges such as poor lighting and privacy issues persist. These challenges can be addressed using thermal cameras; nonetheless, only a few annotated thermal human pose datasets are available for training deep learning-based human pose estimation models. In this regard, we extend our previously released OpenThermalPose dataset with more data, human instances, and poses. In the new OpenThermalPose2 dataset, the number of thermal images increased from 6,090 to 11,391, and the number of labeled humans rose from 14,315 to 21,125. The annotations include bounding boxes and 17 anatomical key points. To show the efficacy of the dataset, we trained and evaluated the YOLOv8-pose and YOLO11-pose models. The experimental results showed that the models trained on the extended dataset outperformed the previous models. We have made the dataset, source code, and pre-trained models publicly available at https://github.com/IS2AI/OpenThermalPose to bolster research in this field.