Extreme heat, the deadliest summer weather-related hazard in the USA, is projected to increase in intensity, duration, frequency, and magnitude, especially in urban areas that account for 80% of the population. Spatial visualization and representation are crucial in establishing the hotspots of vulnerability to the heat hazard. However, despite the progress in the science of vulnerability, there lacks a systematic and consistent conceptual framework. The quantification of variables is unchecked, resulting in subjective decisions regarding the weighting of variables, selection of indicators, and the suitability of the proxies. Moreover, contradicting approaches generate disparate outputs such as; inductive versus deductive, area-based versus population-based, and raster versus vector designs. The qualitative approach, meant to provide supplementary data, is often ignored. This review provides a perspective of the lacunae in the existing literature and builds on these gaps to derive a conceptual framework towards harmonizing theoretical and statistical relationships. The framework is anchored on the longitudinal study approach as the socioeconomic, biophysical, and geodemographic dimensions have an inherent temporal variance. The review calls for a precise and accurate depiction of heat vulnerability in urban areas to inform targeted adaptation and mitigation measures and the long term projection of coupled systems behavior.