This chapter presents a detailed assessment of heatwaves and associated thermal stress across seven Smart Cities of Madhya Pradesh: Bhopal, Indore, Gwalior, Jabalpur, Sagar, Satna, and Ujjain, from 1980 to 2024. Heatwave events were identified using both the India Meteorological Department (IMD) thresholds and a percentile-based approach (95th percentile of Tmax). The study evaluates thermal discomfort using the Humidity Index (HD) and the Universal Thermal Climate Index (UTCI). Results revealed increasing frequency, intensity, and duration of heatwave events, with the northern region (Gwalior and Satna) emerging as the most affected, and the western region (Indore and Ujjain) experiencing fewer but more intense episodes. In addition to heatwave identification, human thermal discomfort was analyzed using the Humidity Index (HD) and Universal Thermal Climate Index (UTCI). HD results indicated high levels of chronic thermal stress across all cities, particularly in central and northern regions, with hundreds of days classified under “Great Discomfort” or “Dangerous” categories. UTCI analysis further highlighted persistent heat stress, with a significant number of days falling under “Moderate” to “Very Strong” stress levels, especially during the pre-monsoon and early monsoon months. The convergence of results from all three indicators underscores a clear rise in regional thermal vulnerability and the urgent need for localized heat action plans, early warning systems, and adaptive infrastructure to mitigate public health risks in the face of evolving climate extremes.