 Dogs, high risk because they only have sweat glands in their feet, and their main way of cooling down is by panting. Very, very easy for them to overheat. Now, again, the chief veterinarian at Petco, dogs with these four main features are the most susceptible if they have flat faces. Short snouts tend to have narrow airways, right? So your pugs, your bulldogs, it's harder for them to breathe and harder for them to pant.