French dogs will die from heatstroke within a few hours. The specific time depends on the dog's constitution and degree of heatstroke. However, if the dog has heatstroke for more than two hours, the mortality rate is relatively high, so it is best not to Give your dog heatstroke. If you find that your dog has heat stroke, you should help the dog to relieve the heat immediately. If the heat stroke is serious or even goes into shock, it is best to send it to a pet hospital for treatment immediately.