Dogs are at risk of overheating during heatwaves, especially in homes without air conditioning. Early signs of overheating include excessive panting, drooling, and difficulty breathing, while severe symptoms may involve vomiting, collapse, or seizures. Flat-faced breeds like French bulldogs and pugs are particularly vulnerable due to their limited ability to regulate body temperature. Without proper precautions, heat stroke can develop rapidly, posing life-threatening risks. Owners should remain vigilant and act quickly if their pets show signs of distress.