
I would just keep an eye on him. If he has sickness and the runs and this continues for a day or so then a visit to the vet should be the next step. I would however just make sure he has plenty of fresh water and is he is sick any more then a bland diet , rice and chicken for a while and some live yogurt may help.
It may well be the heat that has caused this so see how he goes.
Let us know if he is OK.
Lucy