Summer dog tip

I met a vet who told me to pass on the news that on hot summer days do not take your dog on hikes in the middle of the day. He has seen dogs come in for heat stroke this way. He said in summer, at his practice, more dogs die of heat stroke than from rattle snake bites. Take your dog for a walk in the cool morning or in the evening when the sun is down. Someone, not a vet, told me if your dog's tonuge is getting purple than they are getting overheated. I personally don't know if this is true or not.