The present work was designed to assess the effect of vitamin C doses on heat stress in male Zaraibi goats, during summer season. Climatic parameters; including ambient temperature (AT), relative humidity (RH) and temperature humidity index (THI); were estimated under the sunny and shadow conditions. Under sunny circumstances, the climatic parameters were meaningfully elevated as compared to the shadow conditions. The experimental periods (1, 2, 3, 4, 5 & 6 weeks), vitamin C doses (0, 8, 15 and 30 mg/kg body weight) and their interactions exhibited significant effects on all the studied parameters including: rectal temperature (RT), respiratory rate (RR), red blood cells count (RBCC), white blood cells count (WBCC), concentrations of total antioxidant capacity (TAC), triiodothyronine (T3), thyroxine (T4), total proteins (TP), albumin (Alb), total cholesterol (TC), triglycerides (TG), creatinine (Creat) and Urea (U) as well as the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In heat-stressed goats, the RT, RR, RBCC and levels of TP, Alb, TC, TG, Creat, U and activities of AST and ALT were significantly increased as compared to those under shadow, and were correlated positively to the THI, whereas inversely to the vitamin C doses. However, the WBCC, TAC and T3 and T4 levels were reduced with increasing THI, but were significantly enhanced by increasing the dose of vitamin C. In conclusion, the daily vitamin C intake was effective against the signs of heat stress.