India has witnessed some of the unprecedented heat waves that caused substantial mortality. Despite the implications of heat stress on labor efficiency, human health, and mortality, the risk of heat stress under the warming climate is largely unexplored in India. Here, using the observations, reanalysis products, and data from the Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models (GCMs), we show that the risk of heatwaves and heat stress has increased in India during the period of 1979-2017. Both heat waves and heat stress events have become more frequent in the majority of India except the Indo-Gangetic Plain region. In the Indo-Gangetic Plain region, the heat stress has increased while the frequency of heat waves has declined during the observed record of 1979-2017. This contrasting response of heat waves and heat stress in the Gangetic Plain region can be attributed to irrigation and atmospheric aerosols. The risk of heat stress is projected to increase manifold in the majority of India and in the Indo-Gangetic Plain under the 1.5 and 2.0ºC warming scenarios.