Extreme heat exposure is linked to poor maternal and child health. With anthropogenic climate change, global annual temperatures have risen to 1.2°C above pre-industrial levels and are predicted to reach around 2.7°C by the end of the century. West Africa is high-risk for the impacts of climate change, including extreme heat, both in terms of exposure, health risks and adaptation options. This thesis explores the impact of extreme heat on maternal and fetal physiology to improve understanding of the pathophysiological pathways and examines the longer-term impacts of heat on growth in the first 1000 days of life. Firstly, a prospective cohort study was conducted of heat stress, heat strain and fetal strain in pregnant subsistence farmers in West Kiang, The Gambia. Additionally qualitative work explored the lived experiences of pregnant subsistence farmers, to include how working in the heat whilst pregnant feels, what adaptation options are available, and their concerns for the future. Secondly, an analysis of robust data from a randomized controlled trial of nutritional supplementation characterizes the relationship between chronic heat exposure and growth faltering in the first 1000 days of life, also in West Kiang, The Gambia. Thirdly, I engaged schools across The Gambia to identify climate or environmental issues in their areas, develop solutions to these local problems and brought everyone together for a festival to share climate change solutions. The findings showed a worrying level of heat exposure already being experienced. Acute impacts on maternal and fetal physiology were high. Long term impacts of heat on growth faltering were significant for weight-for-age and weight-for-height z-scores. This thesis highlights the ongoing risk to maternal and child health of rising global temperatures, but also demonstrates strong youth and community drive to alter the current trajectory.