If you leave your dog in the car in the summertime, it may be the last time you see it alive.

A car, even with the windows down, interferes with the dog's normal cooling process of evaporation through panting.  This cooling process cannot take place quickly enough in high temperatures.  A dog's normal body temperature is 101.5-102.2°F.  On a hot summer day, 85 degrees for example, your car will heat, within 10 minutes, to 102°F.  In 30 minutes, the temperature will reach 120°F.  On warmer days, the temperature inside your vehicle will go even higher.  If your dog is breathing only hot air, the animal will have a difficult time cooling itself.

A dog can withstand a body temperature of 107-108°F for only a very short time.  A rise in body temperature of only five degrees can cause serious and irreparable brain damage.  To prevent hot weather health problems, it is important to provide plenty of cool water and shade for your pet.  Young and old pets are more vulnerable to heat stress than adults, but all pets are at risk.  Even more at risk are obese dogs and flat-faced dogs like Pugs and Shih Tzus.  Avoid having pets outside during midday when the temperatures are highest. 

Keep animals well groomed to ensure proper insulation, but be aware of haircuts that are too short and leave your pet susceptible to sunburn.  Most pets do not require haircuts to keep them cool because hair acts as a thermoregulator - you may actually make them hotter by shaving off their hair!  Signs of heatstroke include rapid panting, hot skin, twitching muscles, and a dazed look.  If your dog is overcome by heat, you can administer immediate first aid by wetting him all over with cool water or wrapping him in a towel soaked with cool (not cold) water.  In severe cases, immerse the dog in a bathtub or under cool running water.  Then take your pet to a veterinarian right away.