Hot Weather Safety for Dogs: Heatstroke Signs and Prevention

Heatstroke in dogs can progress from mild discomfort to a life-threatening emergency faster than most owners expect, and dogs are less equipped to cool down than we are — they rely mainly on panting, since they sweat only through their paw pads. Knowing the early signs and the real risk factors is what makes prevention effective.

Why dogs overheat faster than people realize

Unlike humans, dogs can't cool themselves through widespread sweating — panting is their primary cooling mechanism, and it becomes far less effective once air temperature and humidity both climb, since panting relies on evaporating moisture into air that isn't already saturated. This is why hot, humid days are more dangerous than hot, dry ones, even at a similar temperature.

Early signs of overheating

• Heavy panting that doesn't ease with rest or shade
• Excessive drooling
• Bright red gums or tongue
• Lethargy or reluctance to keep moving
• Seeking shade or water more insistently than usual

Signs of progressing heatstroke — a medical emergency

• Vomiting or diarrhea
• Stumbling, disorientation, or loss of coordination
• Collapse
• Rapid heart rate
• Pale or bluish gums (a sign of shock, contrasting with the bright red seen earlier)
• Seizures

Any of these signs warrants immediate veterinary attention — heatstroke can cause organ damage quickly, and it's not a wait-and-see situation.

Which dogs are at higher risk

• Brachycephalic (flat-faced) breeds — Bulldogs, Pugs, and similar breeds have less efficient airways for panting and are disproportionately represented in heatstroke cases.
• Overweight dogs — extra weight adds insulation and cardiovascular strain (see our guide to weight management).
• Senior dogs and very young puppies — both have less efficient temperature regulation.
• Thick or double-coated breeds, even though the coat also provides some insulation from direct sun.
• Dogs with heart or respiratory conditions.

Never leave a dog in a parked car

Car interiors heat dramatically faster than outside air temperature, even with windows cracked, and even on days that don't feel extremely hot — a mild 70°F (21°C) day can push a car's interior well past 100°F (38°C) within minutes. This remains one of the most common and most preventable causes of severe heatstroke, and "just a few minutes" is enough time for real danger to develop.

Practical prevention

• Walk during cooler parts of the day — early morning or evening — during hot weather stretches.
• Test pavement with the back of your hand before a walk; if it's too hot to hold your hand on for five seconds, it's too hot for paw pads.
• Always provide accessible shade and fresh water, both outdoors and in any vehicle.
• Never restrict water before or during activity in hot weather, contrary to some older advice.
• Watch brachycephalic and senior dogs especially closely, and consider shorter, more frequent outings rather than one long one.

If you suspect heatstroke

Move the dog to shade or an air-conditioned space immediately, offer small amounts of cool (not ice-cold) water, and apply cool — not freezing — water to the body, particularly the paws, ears, and belly, while heading to a vet or emergency clinic right away. Ice-cold water and ice packs are generally discouraged, as they can cause blood vessels near the skin to constrict, which paradoxically slows core cooling.