Heat and childhood respiratory health: exploring the evidence and raising the red flags

INTRODUCTION: Climate change impacts on the health of vulnerable groups globally. Heat, as a specific component of climate change, affects the respiratory health of children, particularly those from marginalized communities and in low and middle-income countries. Understanding the exposure pathways for these outcomes is critical for interventions and policy development. AREAS COVERED: A synthesis of the evidence for key heat-related childhood respiratory outcomes (asthma, infections, rhinitis and lung function) is presented. The knowledge gaps are highlighted. Interpreting the evidence requires understanding the approaches to heat exposure characterization in epidemiological studies. These exposure-response complexities are explored. EXPERT OPINION: While the evidence for heat-related adverse events among children with asthma and respiratory infections is strong, it is less so for other respiratory outcomes. Inconsistencies exist across studies. These inconsistencies may be as a result of how exposure is characterized in studies. While acute outcomes have been investigated mostly from hospital records, sub-clinical effects among children in community-based studies are absent. Limited studies have been conducted in marginalized communities or in low- and middle-income countries. Understanding exposure-response relationships and addressing gaps in the evidence is necessary for the development of appropriate interventions to protect the respiratory health of children.