Healthcare is an important component of public welfare but is under huge pressure from public health challenges. A surging number of patients during recent pandemics (such as the Covid-19 pandemic) have exhausted medical resources and exceeded the admission capacity of medical institutions. In addition, the increasingly ageing population demands more medical facilities. As contemporary challenges in public health arise, ‘smart city’, a trending strategy that reinforces urban management with advanced institutional instruments and revolutionised technology, is framed as a solution that helps people tackle these problems. However, it is very unlikely that the existing limitations of the smart city solution can be justified as the proper answer to public health. Specifically, this article suggests that (1) smart health can only serve as a technological complement rather than a well-rounded solution to public health for the time being; (2) while smart healthcare services have empowered people in New York City, Chicago and Louisville with hope to enhance efficiency and promote wellbeing, there are constraints due to a lack of connection to a wider smart city plan, potential subjective and unreliable data sources, as well as the narrow range of application and limited impact; (3) the concerns around data security and privacy can impede smart health from being implemented, and smart health requires multi-disciplinary and multi-agent coordination. This article reveals the gap between existing proposed strategy and regional practices - taking New York City, Chicago and Louisville as case studies. Furthermore, it provides an evaluation of smart health, covering advantages, limitations, and possible directions for improvement.