The study aimed at evaluating the adaptive physiological capacity of Sasso laying hens in a hot-dry environment. Fifty four randomly selected 30-week old Sasso layers were each kept on deep litter and in battery cages. General Linear Model was used to determine the fixed housing system and age (42 and 52 weeks old, respectively) effects including their interaction with thermo-physiological traits [rectal temperature (RT), respiratory rate (RR), pulse rate (PR) and heat stress index (HSI)] while Exhaustive CHAID algorithm was used to predict HSI. Haematological and serum biochemical indices considered were subjected to T- test at 52 weeks of age. The mean environmental Temperature-Humidity index (79.92) indicated that the birds experienced thermal discomfort. Univariate analysis revealed that birds kept in battery cages appeared to be more stressed with higher mean values (P