The Himalayan forests provide many ecosystem functions to about 18% of the global population, including ensuring water security, agricultural benefits, carbon sequestration, groundwater recharge, medicinal benefits, etc. The longevity of the Himalayan forest ecosystems is also critical for the survival of the seven Himalayan nations, because they form the headwater regions of all the major rivers of Asia. In recent years, however, the Himalayan forests have been suffering from multiple natural and anthropogenic threats. While the effects of different threats are well researched in the Himalayan forests, studies documenting the effects of heatwave-induced stress (heat stress) are rare. The present review aims to fill this literature gap by extrapolating global heat stress mechanisms to Himalayan vegetation zones to predict vulnerabilities. The review study uses different scientific literature databases to derive conclusions on the effect of heat stress in the Himalayan forest ecosystems.