Recent pose-based gait recognition methods, which utilize human skeletons as the model input, have demonstrated significant potential in handling variations in clothing and occlusions. However, methods relying on such skeleton to encode pose are constrained mainly by two problems: (1) poor performance caused by the shape loss, and (2) lack of generalizability. Addressing these limitations, we revisit pose-based gait recognition and develop GaitHeat, a heatmap-based framework that largely enhances performance and robustness by utilizing a new modality to encode pose rather than keypoint coordinates. We make our efforts from two aspects, the pipeline and the extraction of multi-channel heatmap features. Specifically, the process of resizing and centering is performed in the RGB space to largely preserve the integrity of heatmap information. To boost the generalization across various datasets further, we propose a pose-guided heatmap alignment module to eliminate the influence of gait-irrelevant covariates. Furthermore, a global-local network incorporating an efficient fusion branch is designed to improve the extraction of semantic information. Compared to skeleton-based methods, GaitHeat exhibits superior performance in learning gait features and demonstrates effective generalization across different datasets. Experiments on three datasets reveal that our proposed method achieves state-of-the-art results for pose-based gait recognition, comparable to that of silhouette-based approaches. The code will be made available upon acceptance.