With temperatures in the high 20s this week the hens have been looking for shade as even the hen houses are too hot. The garden wall is popular, its shaded and there's a slight breeze when you are 50cms off the ground.
Its a problem for the globalised poultry meat industry too. Dwarf strains of meat type poultry with naked necks to maximise heat loss have been developed. Feather growth on the head and neck is inhibited. This gene is combined with a "dwarf gene" in the breeding females which have a lower food intake, the breeding hens are therefore smaller and easier to manage. The offspring are not affected and have high growth rates.
Meanwhile back at the croft there aren't any dwarf genes that I know of, the hens have a full complement of feathers and plenty of shade to simulate the N. Indian jungle environment.