This study aimed to investigate how to enhancing the resistance of broiler chicks to hot climate by using both early heat shock exposure and glutamine injection (GI). A total of 360 male chicks, one-day old of Cobb breed were randomly distributed into equal 6 treatments each of three replicates . The experimental groups were arranged as follows: the 1^st group (T1) used as a control and reared under natural conditions, the 2^nd group (T2) exposed to heat challenge (33±3ºC) from one up to 38 days of age, the 3^rd group (T3) exposed to early heat shock (41±1ºC for four hours from 12:00 pm till 16:00 pm for 3 consecutive days) at the 3^th up to 5^th   days of age, the 4^th group (T4) was injected  with Gl 0.75 mg/kg weight at the 2^th day of age, then Exposed to early heat stress shock as in T3 ,the 5^th group (T5) was exposed to heat shock (41±1ºC for four hours from 12:00 till 16:00 for 3 consecutive days) at the 3^th up to 5^th and 15^th up to 17^th days of age, and the 6^th group of chicks (T6) were injected  with Gl (0.75 mg/kg weight) at the 2^th and 14^th day of age then exposed to early heat shock as T5 group. Results revealed that live body weight , body weight gain and feed conversion ratio were improved for chicks in T4 and T6 groups than other treatments with or without significant effect. Some blood constituents , antioxidant statues and immune parameters were affected treatments. Relative heart and Gizzard weights were significantly increased for all treatments as compared with the control expect of T3 group . Results indicated that glutamine injection (0.75 mg/kg BW)at the 2^th and 14^th days of age for broiler chicks then exposed to induce early heat stock at the 3th up to 5^th and 15^th up to 17^th  3 and 15 days of age might be improved productive and physiological performance during rearing period.