Climate change and its impact on the agricultural sector are one of the most important challenges for adaptation especially in livestock production. Increasing social concerns for sustainable agriculture strongly influences animal breeding systems. Poultry production is a major source of proteins for human food worldwide and in a context of growing human population, it is essential to work towards better adaptation of poultry to heat stress and limitations on feed. We propose to address this broad and challenging question from a biological perspective by analyzing the epigenome of chickens, which is known to be modulated in response to environmental variations. To understand the molecular mechanisms underlying chickens’ response to heat stress, high-throughput epigenomics data (DNA methylation) have been generated in offspring whose parents were exposed to a heat stressed environment or not. All birds were reared under standard conditions (22°C, ad libitum feeding). In the heat stress and control experiments, hens were reared at 22°C until 28 weeks of age. Between 28 and 32 weeks of age, in the heat-stressed group, hens were subjected to a temperature of 32°C (increasing by 2°C per hour for 5 hours). Their eggs were collected between 31 and 32 weeks. Reduced representation bisulfite sequencing (RRBS) sequencing data (Illumina, 50bp single-end) was performed on the whole brains of 22 embryos (10 controls and 12 stressed) at 12 days of age, derived from hens with or without heat stress. RRBS data were analyzed with the nf-core/methylseq pipeline. The Bioconductor package edgeR was used to detect differentially methylated cytosines (DMC) and differentially methylated regions (DMR). We detected a total of 289 DMCs and one DMR between offspring of heated stressed mothers and controls. These DMCs were associated with 358 genes, which play an important role in processes such as cellular response to stimulus and developmental processes. Overall, this study provides valuable insights into the adaptive mechanisms involved in the response of chicken embryos to heat stress in their mothers. These results show that heat stress of hens can mediate changes in the methylation patterns of offspring during the embryonic stage, possibly influencing their response to later exposures of heat stress.