By late morning in south-west London, the mercury had already climbed to 32.8C at Bushy Park in Teddington, provisionally equalling the hottest May temperature ever recorded in Britain, according to the Met Office. The previous benchmark was set in 1944.
For humans, it is the sort of extraordinary heat that prompts packed beer gardens, hastily bought fans and a collective national obsession with ice cream. For dogs, however, it can be lethal.
Every summer, vets and animal charities issue the same warnings, and every summer many owners still underestimate just how quickly dogs can succumb to heatstroke. Yet the danger is not confined to cars left baking in supermarket car parks. According to the RSPCA, dogs are actually far more likely to develop fatal heat related illness while exercising in hot weather than from being trapped in vehicles.
Dogs do not sweat like humans. They rely primarily on panting to regulate body temperature, which becomes dangerously ineffective in extreme heat. Once their temperature rises too high, organs can begin to fail with terrifying speed.
And on a day like today, when pavements shimmer and the air itself feels heavy, even an ordinary lunchtime walk can become hazardous.
The warning signs are distressingly easy to miss at first, frantic panting, excessive drooling, lethargy, wobbliness, vomiting. Some dogs simply collapse. The breeds most at risk are flat faced dogs such as pugs, bulldogs and French bulldogs, whose shortened airways make cooling themselves especially difficult. Older dogs, overweight pets and animals with heart or breathing conditions are also highly vulnerable.
The most important advice from animal welfare experts is deceptively simple, rethink the routine.
The familiar afternoon dog walk, a cherished British habit in parks, commons and along canal paths, may need to disappear entirely during heatwaves. The RSPCA’s hot weather guidance urges owners to walk dogs only in the coolest parts of the day, ideally early morning or late evening.
Then there is the pavement itself. Tarmac can become scorching within minutes under direct sun, capable of burning paw pads severely enough to require veterinary treatment. The rule experts repeat is blunt and memorable, if you cannot comfortably hold the back of your hand on the pavement for five seconds, it is too hot for your dog.
At home, shade and ventilation are essential. Dogs should have constant access to fresh water, preferably replenished frequently. Some owners add ice cubes to bowls or provide damp towels for pets to lie on. Others freeze dog safe treats or use paddling pools to help animals cool themselves gradually.
Cars, meanwhile, remain among the deadliest environments imaginable for animals in hot weather. The statistics are stark, when temperatures outside reach just 22C, the inside of a vehicle can soar to 47C within a short time. On a day exceeding 32C, conditions become catastrophic extraordinarily quickly.
The old myths persist, “the windows were open”, “I was only gone for five minutes”, “the car was parked in shade”, but experts insist none of these precautions make a parked car safe.
If a dog appears distressed inside a hot vehicle, the advice is to call 999 immediately. The RSPCA notes that while breaking a window may be legally defensible in an emergency, it could still amount to criminal damage and should only be considered if the animal is clearly in imminent danger and police have been contacted.
Perhaps the most sobering reality is how rapidly heatstroke escalates. Veterinary specialists now promote a phrase every dog owner should remember, “cool first, transport second”.
If a dog is overheating, owners should immediately move them into shade, stop exercise, pour cool, but not ice cold, water over the body, especially the stomach, thighs and neck, and create airflow with a fan or breeze. Wet towels draped over the body can sometimes trap heat rather than release it. Once the dog begins cooling, veterinary help is urgent.
While humans can adapt with sunscreen, cold drinks and lighter clothing, our pets remain entirely dependent on our judgement.
And on a record-breaking May afternoon, that judgement matters more than ever.
Find out more about caring for your dog in hot weather from the RSPCA here.
