Heatwaves not only bring irreversible shock to natural eco-systems but also have a significant negative impact to the economy and health of the human society. Western scholars have primarily investigated the extreme temperatures of the heatwaves and have produced significant results. In the present article, we first identified the research ideas on heatwaves in western countries, i.e., to identify its connotation from the perspective of measure, to analyze the mechanism from the perspective of simulation and comparison, to summarize the distribution and laws from the spatial perspective, to explore its effect from the perspective of composite system, and to assess the level of hazard from the perspective of epidemiology. Second, some contradictions and focal points are highlighted, including mechanism analysis, impact assessment, vulnerability assessment, risk perception, and adaption analysis. Third, references to China were presented, such as expanding the empirical study on typical regions, identifying vulnerable groups and underdeveloped areas, focusing on health and especially the effects on mental health, trying to broaden the research fields and integrate multidisciplinary approach.