Only after walking barefoot on the scorching ground one summer did I know what 'feet steamed by the hot summer earth' means.
Tips
history
From 白居易's 观刈麦 of 806, describing reapers in the wheat fields: 足蒸暑土气，背灼炎天光 'feet steamed by the hot summer earth, backs scorched by the blazing sky'. The two lines match word for word, feet with backs and earth with sky.
usage
土 and 气 here are the ground and the heat rising off it, nothing to do with the modern word 土气 'rustic'. 暑 is the heat of high summer, as in 暑假 'summer holidays'.
