The rise in global temperature increases the frequency, intensity and duration of heatwaves worldwide. This study examines their evolution in Senegal under two global warming scenarios: + 1.5 and + 2 °C. Based on the excess heat factor (EHF) index and heat index (HI), different characteristics of heatwaves and health risks have been highlighted using ERA5 reanalysis, Princeton observation data, as well as simulations from four global climate models of the ISIMIP2b project from the CMIP5 program. Results show that during the historical period, the eastern and central regions of the country are most affected by heatwave characteristics, with moderate health risks during the cold season (OND and JFM), and high risks during the hot season (especially AMJ). Under the + 1.5 °C scenario, the number of heatwaves increases, while under + 2 °C, they become longer and more intense, and also affect the western part of the country. The HI indicates a clear worsening of heat stress, with an expansion of “Extreme Caution” zones, particularly inland, in the north and south. Limiting warming to + 1.5 °C would reduce heat stress by approximately 3.