Summer heat: Learn how to protect your dog from heatstroke
Summer is here, and for your dog, that’s not always a good thing. Dogs can’t cool down the way we do. They can’t sweat (except a tiny bit through their paw pads).
Their main cooling tools are panting and dilating blood vessels near the skin.
When the heat overwhelms those two systems, body temperature spikes fast. That’s heatstroke, and it can go from manageable to life-threatening in minutes.
The good news? You can prevent it. And if it does happen, knowing exactly what to do could save your dog’s life.
Quick reference: Heatstroke checklist
At a glance, here’s everything you need to know.
What is heatstroke?
Heatstroke happens when your dog’s internal temperature rises above 105°F (the normal range is around 101.5°F). At that point, the body’s cooling systems can’t keep up. If the temperature climbs to 107–109°F, organ failure sets in. That’s a potentially fatal situation.
Marvelous Dogs say that canines can experience hyperthermia for many reasons, such as disease, exercise, and environmental temperature.
There are two main causes of heatstroke: exertional heatstroke (too much exercise in the heat) and environmental heatstroke (being stuck somewhere hot without escape—like a parked car or a sun-baked backyard). Both are serious. Both are preventable.
Dogs cool themselves through two mechanisms:
- Panting — moisture evaporates from the tongue, nasal passages, and lungs, carrying heat out of the body
- Vasodilation — blood vessels near the skin (especially in the ears and face) expand to release heat
When heat overwhelms both, internal temperature rises rapidly. Minutes matter.
The heatstroke danger zone: May through September
Risk peaks during summer, but heatstroke can strike any time temperatures soar, or when a dog exercises too hard in mild weather.
Here’s a simple guide for reading your local heat index:
The pavement test: Press your palm flat on the sidewalk for 5 seconds. If it burns your hand, it’ll burn your dog’s paws — and it’s too hot to walk.
The safest rule? Walk your dog before 9 a.m. or after 7 p.m. from May through September. If the heat index tops 103°F, skip the outdoor walk entirely.
What are the early warning signs of heatstroke?
Heat stroke moves fast. The early signs can look mild, which is exactly why people miss them.
But it’s a life-threatening condition, so don’t wait for things to get worse — act at the first signal.
Early warning signs or symptoms of heatstroke (act now)
- Heavy or excessive panting
- Slower pulses
- Rapid breathing or difficulty breathing
- Dry nose
- Excessive drooling
- Tongue hanging out further than normal
- Dry mouth and gums (dehydration)
- Lethargy
- Bright red gums and tongue
- Hot skin to the touch
- Rapid heart rate
- Vomiting or diarrhea
- Weakness or unsteadiness
- Heat cramps
Late-stage signs (emergency)
If your dog reaches this point, they’re in shock. Get to a vet immediately.
- White or bluish gums (severe dehydration and shock)
- Very rapid or irregular heartbeat
- Drop in blood pressure
- Disorientation or confusion
- Dilated pupils
- Muscle tremors or muscle spasms
- Collapse or seizures
Emergency cooling protocol: Step-by-step
If you think your dog has heatstroke, every second counts. Follow these steps in order:
- Move your dog to a cool, shaded or air-conditioned area immediately.
- Offer small sips of cool water. Don’t force it or let them gulp it all at once.
- Apply cool (not ice-cold) water to your dog’s fur and skin — focus on the neck, armpits, and groin where blood vessels run close to the surface.
- Use a fan or natural breeze to speed up evaporative cooling.
- Place cool, wet towels on your dog, especially on the neck and paw pads.
- Check your dog’s temperature with a rectal thermometer if you have one.
- If the temperature is above 105°F — or if you don’t have a thermometer and your dog isn’t improving within 10 minutes — call your vet or head to an emergency clinic now.
- Stop active cooling once the temperature drops to around 103°F to avoid overcorrection.
Avoid ice water or ice baths. Rapid cooling causes blood vessels to constrict, trapping heat inside the body and worsening the situation.
When to call the veterinarian: Decision tree
Not sure whether this is a watch-and-wait situation or a rush-to-the-ER moment? Use this.
Even if your dog makes a full recovery at home, call your vet.
Organ damage from heatstroke can be invisible at first and show up hours — or even days — later.
How is heatstroke treated in dogs?
At the clinic, treatment depends on the severity of the heatstroke. Mild cases might need monitoring and IV fluids. Severe cases require oxygen, medication, and in-hospital support for 24 to 72 hours.
Because heatstroke can trigger secondary conditions like kidney failure, clotting disorders, and brain damage, your vet will likely want to monitor your dog closely even after they seem fine. Follow-up appointments aren’t optional — they’re part of the treatment.
What’s the prognosis after heatstroke?
It depends. Dogs whose temperature didn’t spike too high and who got treated quickly usually make a full recovery.
But severe heatstroke can cause permanent organ damage. And here’s a sobering reality: dogs who’ve had heatstroke once are more prone to it again, because heat-related damage to the brain’s thermoregulatory center can make future regulation harder.
Factors that influence heatstroke risk
Several things make some dogs more vulnerable than others. Risk factors include:
- Breed (see below)
- Age — puppies and older dogs are more vulnerable
- Weight — overweight dogs struggle to regulate temperature
- Fitness level — unfit dogs overheat faster
- Existing medical conditions like heart or respiratory disease
- Environment — humidity matters as much as temperature
- Access to water and shade
- Acclimation — a dog that’s been indoors all winter isn’t ready for a hot summer day
Which breeds are most at risk?
All dogs can get heatstroke. But some dog breeds are at the front of the line for risk:
Flat-faced (brachycephalic) breeds like English Bulldogs, French Bulldogs, Boston Terriers, and Pugs have narrow airways that make efficient panting nearly impossible.
They’re always working harder to breathe — and in the heat, that work becomes overwhelming.
Long-coated breeds like the Golden Retriever, Siberian Husky, and Chow Chow trap more heat.
But don’t reach for the clippers — their double coat actually insulates against both cold and heat, and shaving it increases the risk of heatstroke and heat exhaustion.
Golden Retrievers and Labradors are also prone to laryngeal paralysis, a condition that makes it hard for them to open their larynxes when panting fully.
Myths vs. facts about dog heatstroke
There’s a lot of bad advice floating around. Let’s set the record straight.
How to prevent heatstroke
The best treatment is never needing one. Here’s how to keep your dog safe:
- Walk your dog at dawn or dusk during hot months — never mid-day
- Always carry water and a portable bowl on outings
- Provide shade — a tree, umbrella, or covered porch all work
- Never leave your dog in a parked car, even for two minutes, even with windows cracked
- Use cooling mats or damp towels for rest breaks
- Protect paws from hot pavement with the 5-second hand test
- Set up a kiddie pool or sprinkler for backyard fun
- Use pet-safe sunscreen on dogs with thin or light-colored coats
- Keep up with summer grooming — brush out the undercoat to improve airflow, but skip the shave
Help your dog acclimate to warmer temperatures
A dog that’s been inside all winter isn’t ready to run a 5K in July. Give their body time to adjust.
Start slow
When warm weather arrives, start with shorter walks and gradually build up duration over two to three weeks. This gives your dog’s cooling systems time to adapt.
Shade and water — non-negotiable
Ensure your dog always has access to shade and a fresh supply of cool water, especially outdoors.
Skip peak heat hours
Avoid strenuous activity between 10 a.m. and 5 p.m. from late spring through early fall.
Never leave your dog in a hot car
Even on a 70°F day, a car interior can reach 89°F within minutes. On an 85°F day, it can hit 120°F within half an hour. Leave your dog at home if you have errands to run.
Watch for signs of heat stress
Stay vigilant for heavy panting, drooling, a rapid heartbeat, or weakness. Move your dog to a cooler area if any of those appear, and call your vet if they don’t resolve quickly.
Hydrate, hydrate, hydrate
- Keep cool, fresh water available at all times. Change it at least twice a day in hot weather
- Place multiple water bowls around the house and yard, so your dog always has easy access
- Bring a portable water bottle and bowl on every outing — even short ones
- Add water-rich foods to your dog’s diet: cucumbers, watermelon (seedless), and wet food all help
- Drop a few ice cubes in the water bowl to keep it cool and make it more appealing
Check out our guide to keeping your dog hydrated while traveling for more tips on the go.
Keeping cool without AC or a yard
No air conditioning? Small apartment? No problem. Here are practical cooling hacks for urban dog owners:
- Use a cooling mat — gel-filled mats stay naturally cool and don’t need refrigerating
- Set up a box fan facing your dog’s bed. Combine with a damp towel for DIY evaporative cooling
- Wet a bandana and wrap it around your dog’s neck before walks
- Freeze a Kong or lick mat with wet food or plain yogurt — it cools from the inside out
- Close blinds and curtains during peak sun hours (usually 10 a.m. to 3 p.m.) to keep indoor temps down
- Tile floors are naturally cooler — let your dog stretch out on them during peak heat
- Schedule playtime and walks before 9 a.m. and after 7 p.m. entirely
- Consider a cooling vest for walks — soak it in water and let evaporation do the work
- A small kiddie pool on a balcony or in a hallway can give relief in a pinch
Use cooling products
The market for dog cooling gear has exploded — and a lot of it actually works. Here’s what’s worth considering:
- Cooling vests — soak them in water; evaporation keeps your dog cool on walks
- Cooling mats — gel or pressure-activated fabric that stays cool without refrigeration
- Cooling bandanas — soak and tie around the neck for quick heat relief
- Outdoor pools — portable, dog-safe splash pools that pack flat for storage
- Cooling towels — lightweight, moisture-wicking towels you can drape over your dog
- Battery-operated fans — clip-on or freestanding, great for crates and small spaces
- Frozen treats — a stuffed frozen Kong isn’t just fun; it brings your dog’s core temp down from the inside
Don’t forget about the temperature inside
Indoors doesn’t automatically mean safe. A stuffy apartment with no ventilation can reach dangerous temperatures on a hot day, especially upper floors that trap heat.
Here’s how to keep indoor temps manageable:
- Use fans or air conditioning to maintain a comfortable temperature
- Close blinds and curtains on sun-facing windows during the day
- Open windows in the early morning and late evening when outdoor air is cooler
- Keep your dog off hot tile or laminate flooring that’s been baking in a sunny room
- Monitor the temperature in your dog’s usual spots — it can vary significantly room to room
Frequently asked questions about dog heatstroke
How quickly can heatstroke kill a dog?
Fast. Body temperature can spike to dangerous levels within minutes of exposure to extreme heat. Without treatment, organ failure can set in within 30 to 60 minutes of a severe episode.
Can dogs get heatstroke indoors?
Yes. A hot, poorly ventilated room — especially on an upper floor — can be just as dangerous as direct sun. Parked cars are the biggest indoor risk, but apartments without AC aren’t far behind on extreme heat days.
What temperature is too hot to walk a dog?
If the heat index reaches 103°F or higher, walks should be limited to brief bathroom breaks only. At 90°F with high humidity, that already feels like 103°F to a dog. Always apply the pavement test: 5 seconds, palm down. If it burns you, skip the walk.
Should I give my dog ice water to cool them down?
No. Ice water causes blood vessels to constrict, which actually traps heat inside the body. Use cool (not cold) water. Ice cubes in a bowl for drinking are fine — it’s splashing ice water on the body that causes the problem.
Is it OK to shave my dog in summer?
For double-coated breeds, no. Their undercoat acts as an insulating layer that protects against both heat and cold. Shaving it disrupts that system and actually increases the risk of heatstroke. For short-haired or single-coat breeds, a light trim can help — but check with your groomer or vet first.
Can dogs recover fully from heatstroke?
Many do, especially with fast treatment. But severe episodes can cause lasting damage to the kidneys, liver, brain, or blood-clotting system. Dogs who’ve had heatstroke once are more susceptible to it again, so prevention becomes even more critical in the future.
How do I keep my dog cool if I don’t have air conditioning?
Use cooling mats, damp towels, fans, and frozen treats to manage heat indoors. Walk only before 9 a.m. and after 7 p.m. Close sun-facing blinds during the day. Tile floors are your dog’s best friend on hot days. See our tips above for more specific ideas.
Final thoughts on preventing heatstroke
Your dog wants to be where you are — on summer hikes, backyard cookouts, weekend adventures. That’s the whole point. But they’re counting on you to read the situation, because they can’t tell you when they’re struggling.
If you’re feeling the heat, your dog is feeling it more. Plan walks around the temperature, keep water everywhere, and know the warning signs. Heatstroke can develop in minutes — but with the right knowledge, it’s almost entirely preventable.