Fibers and textiles play key roles in the development and day-to-day activities of human society. Innovations related to flexible electronics-smart fibers and textiles with sensing, thermal regulation, and energy management capabilities-have drawn great interest from both academic and industrial communities. Smart fibers and textiles are anticipated to revolutionize personal health management due to their manifold features and capabilities, providing the foundation for many intelligent wearables. In this Perspective, we provide a brief overview of recent advances in the design and fabrication of smart fibers and textiles for health management applications, focusing primarily on those with sensing, thermal regulation, and energy management functions. We describe the existing challenges and opportunities and propose future development directions.