This study was conducted to explore the benefit of adding synthetic and natural antioxidants nutritional additives in drinking water to increase broiler resistance to heat stress in the hot summer climate on productive performance, and physiological status. A total of 600 chicks of broiler (Ross-308) were distributed into ten treatments, each treatment with three replicates of 20 chicks. The treatments of study are: T0: (Positive control: drinking water without adding-DW)- without heat stress, treatments exposed to heat stress: [T1: (Negative control: drinking water without adding-DW, but exposed to heat stress), T2: (100 mg BHT/1 L DW) (BHT – butylhydroxytoluene: synthetic antioxidant), T3: (100 mg vit E/1 L DW) (synthetic antioxidant), T4: (200 mg saffron/1 L DW) (natural antioxidant, T5: (200 mg curcumin/1 L DW), T6: (100 mg saffron+ 50 mg BHT/1 L DW), T7: (100 mg saffron+50 mg vit E/1 L DW), T8: (100 mg curcumin+ 50 mg BHT/1 L DW), T9: (100 mg curcumin+ 50 mg vit E/1 L DW)]. Data of the study analyses and display that the synthetic and natural antioxidants nutritional additives had significantly decreases in the temperature of body parts surface (head, back, under wings, cloaca), general body temperature, mortality%, Malondialdehyde (MDA), heat shock proteins (HSP-40 and HSP -70), Corticosterone hormone concentration in the blood serum and heterophiles: lymphocytes (H/L) ratio. However, body weight, body weight gain, Production index (PI), feasibility (economic profit), water intake (WI), Glutathione Peroxidase (GSH-Px), super oxide dismutase (SOD), total antioxidant capacity (TAC), Newcastle (ND), Infectious bursal (IBD) diseases and Infection bronchitis virus (IB), so feed conversion ratio (FCR) had significantly improved in the all treatments of water additive in the treatments of positive control T0 compared with the negative control T1. Whereas, feed intake had non-significant differences among all treatments of the study. In all traits of the study natural antioxidant additives: saffron and curcumin additives seen superiorly