LanternPet › Hot-weather safety

Hot weather and your dog: pavement, sun, and water

The number on your phone is the air temperature five feet up. Your dog walks on the ground, in a fur coat, and cannot sweat. In full sun, asphalt runs roughly 30 to 50°F hotter than the air, which is well into the range where contact burns happen.

Seven seconds, back of your hand

Press the back of your hand flat on the pavement and hold it for seven seconds. If you have to lift it early, so would they, and they have no choice about where you walk. Use the back of your hand rather than your palm: the skin there is thinner and closer to how a paw pad feels it.

Why the ground is so much hotter than the air

Dark pavement absorbs sunlight and holds it. That is why the gap widens as the day goes on, and why a road that felt fine at 8am can be dangerous at 4pm and still too hot at 8pm.

If your dog lives outside

An outdoor dog on a hot day needs more than a bowl and a doghouse. Four things matter, and the second one surprises people.

1. Shade that moves with the sun. The shady spot you left them in at 10am is in full sun by 2pm. Check where the shade actually falls in the afternoon, not the morning.
2. A doghouse is not shade. An enclosed box in the sun traps heat and cuts airflow, so it can be hotter inside than out. A raised tarp, a covered porch, or a tree is better on a hot day.
3. Water in the shade, in more than one bowl. A metal or dark bowl in the sun gets genuinely hot, and one tipped bowl means no water for hours. Two heavy bowls in different shaded spots is cheap insurance.
4. Somewhere to get off the hot ground. A raised cot, a mat, or a dug patch of cool earth. Bare dirt and concrete both radiate heat back up at them all afternoon.

Water

Dogs cool themselves by panting, which means they lose water fast in heat. Offer it constantly rather than on a schedule, and bring some on any walk longer than a few minutes.

Cool water is fine. There is a persistent belief that letting a hot dog drink cold water causes bloat or shock, and it is not supported. Do not withhold water from an overheated dog. The one thing to avoid is letting them gulp an enormous volume at once, so offer moderate amounts often.

Some dogs are in trouble much sooner

If yours is on this list, the thresholds above are optimistic:

• Flat-faced breeds — pugs, bulldogs, French bulldogs, boxers, Persian cats. Panting is how a dog sheds heat, and a shortened airway makes it much less effective. These dogs get into serious trouble on days other dogs handle easily.
• Thick or double coats — huskies, malamutes, chows, Newfoundlands.
• Overweight dogs — more heat produced, more insulation, less efficient cooling.
• Seniors, puppies, and any dog with heart or airway disease.
• Dark coats, which absorb noticeably more sun.

Cars

A parked car on a warm day becomes an oven within minutes, and cracked windows do not meaningfully change that. There is no safe duration. Leave them home.

This guidance is not a substitute for professional veterinary care. When in doubt, call your vet.

Where these numbers come from. The 30 to 50°F range, the shade figure, and the burn thresholds come from measured surface temperatures reported in "Streets of Fire" revisited (Burns & Trauma, 2019), which recorded Phoenix asphalt at 138.5°F at noon in August 2018 against a 106°F ambient median, the same asphalt at 109°F in shade, and 124.5°F by 6pm. Burn thresholds by surface temperature trace to the contact-burn literature that paper reviews, beginning with Berens (JAMA, 1970).

We deliberately do not use the air-to-asphalt chart that circulates on pet-safety sites (77°F air giving 125°F asphalt, 86°F giving 135°F, 87°F giving 143°F). Two problems with it. It is not internally consistent: those rows add 48°F, 49°F, and 56°F to the air temperature, so no single line passes through all three. And fitting a line to the first and last of them and extending it does not survive contact with measurement — at the 106°F ambient above it predicts about 177°F where 138.5°F was recorded.

The likeliest explanation is a transcription error that then spread: if that last row was originally 95°F giving 143°F, the three rows add 48°F, 49°F, and 48°F, which is a near-constant offset and agrees with everything else here. We cannot prove that from the original paper, so it stays an inference — but it is why this page uses an offset band rather than a slope.

An independent check from road engineering lands in the same place. The Transportation Research Board's latitude model for maximum pavement temperature, ΔT(°C) = −0.0062φ² + 0.2289φ + 24.38, gives about +42°F at Utah's latitude — inside the 30–50°F band, and nowhere near +64°F.

Ranges are more honest than a line, because sunlight heats a road and air temperature only correlates with it. Changing solar radiation alone, with air temperature held constant, moves measured pavement temperature by around 20°F. An overcast 90°F day and a cloudless one are not the same, and no air-temperature-only estimate can tell them apart.

On burn times. Surfaces above roughly 111°F are where contact burns start being documented, and the risk climbs steeply from there. This page deliberately gives no burn times, because the figures in circulation come from human skin and we could find no validated time-and-temperature curve for canine paw pads, which are thicker, keratinised, and in intermittent rather than sustained contact while walking. Treat the numbers as a reason to check, and the seven-second hand test as the answer.