A dog can only withstand a HIGH body temperature (excess of 103 °F)  for a short time before suffering nerve damage, heart problems, liver damage, brain damage or even death. Most likely they will die from heatstroke in just 15 minutes.

Signs of heat-related illnesses include:

• Excessive panting
• Excessive drooling
• Increased heart rate
• Trouble breathing
• Disorientation
• Collapse or loss of consciousness
• Seizure
• Respiratory arrest