A warming planet and persistent increases in temperature and humidity experienced by humans call for an urgent focus on which indicators of excess heat are the most informative. Several heat indicators have been developed to assess past heat conditions and inform future actions. We compare and contrast the relative merits of two indicators, namely, the heat index and the excess heat factor in urban contexts. Both the indicators have been used by official agencies in high income countries, such as the United States of America and Australia, and are also receiving increasing attention in India. The analysis presents a new approach towards assessing the usefulness of a heat indicator, wherein the indicator acquires value when placed in specific stress contexts. A two-step approach is adopted. First, an analytical framework of the urban heat-health issue is developed, based on the interdisciplinary expertise of the authors, and the framework is used to assess the two indicators. Second, data from two Indian cities located in different climatic zones, one experiencing very dry heat and the other very humid heat conditions is used to compute, compare and contrast the findings from the two heat indicators. The computation uses R software with data from the Ogimet repository and the Indian Meteorological Department. Findings reveal that the indicators are distinct but complementary and if used together can lead to a more effective strategy for reducing heat-health risks for Indian cities. An interactive graphical tool is provided to help the interested reader explore the indicators.