Abstract Background Increased ambient temperatures and extreme heat events are well-established risk factors for increased mortality and morbidity. Most studies to-date have focused on the effect of high temperature on adult populations. However, the paediatric population is vulnerable to increased temperatures, due to a combination of physiological and social vulnerabilities characteristic of children. This presentation will present the findings of a systematic review and meta-analysis on increased heat and childhood health risks. Methods A literature search was carried out of three scientific databases: Pubmed, Embase, and SCOPUS. The data was pooled and summarised in statistical meta-analysis, and presented as relative risk (RR) scores. Subgroup analyses by disease category, gender, and climate group were carried out. Studies not meeting criteria for statistical meta-analysis were summarised in narrative review. Results There is evidence that increased heat increases all-cause mortality in the paediatric population. Increased heat is a risk factor for morbidity throughout the childhood years, from increased rates of preterm birth, to increased adolescent mental health presentations. There is evidence that heat increases the risk of SIDS, respiratory, heat illness, renal disease, mental health, and infectious diseases in children. The majority of studies which quantified the relationship between increased heat and illness do not separate children from adults in statistical analyses. Conclusions There is a substantial body of evidence demonstrating that children have higher rates of morbidity and mortality as a result of higher than usual temperatures. Further research is required into the effects of global warming on child health, and more research is needed to establish protective factors. Researchers in environmental health should consider sub-group analyses on children to identify risks particular to this vulnerable population Key messages • Children are at increased risks of multiple diseases in hot temperatures or heatwaves. • More research is needed into the unique impact of climate change on children.