Heat is an important abiotic stress factor which intensified in recent decades due to globally increasing temperatures. Heat stress (HS) has severe adverse effects on plant growth and agricultural production. Therefore, understanding crop responses to HS is important for developing strategies to increase their resilience in a changing climate. We propose a project aiming to analyze the effects of HS with a focus on nuclear organization and epigenetic regulation in barley. The work is structured into three work packages: (i) Analysis of HS-induced chromosome and chromatin changes by microscopic methods and Hi-C, (ii) Study of transcriptomic and epigenomic responses of barley to HS by RNA-seq and ChIP-seq, and (iii) Exploring effects of HS on transposon mobility in barley with Mobilome-seq, followed by molecular and genetic analyses. By cutting-edge genome biology and physiology, this pioneering study will reveal the effects of HS on the organization and regulation of the barley genome and will provide knowledge for designing more heat-tolerant cereals.