Dehydration. Have some water and pure coconut water on hand.
I recently read an article about a dog who died due to this...hot weather, stuck in crate on the tarmack - was not attended to properly as they are treated as cargo...this was an airline that promoted safe pet travel.
The poor owners could see their dog collapsed with tongue hanging out and couldn't get to it
He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. - Unknown