In short
- On a typical summer day, a parked car can get 30 to 40 degrees hotter inside than the air outside.[2] No child, adult who needs care, or pet should be left in one, even briefly.[3]
- Before you drive, open the doors for a minute, run the air-con on fresh air, then switch to recirculate once the cabin cools.
- Carry water and plan longer trips for the cooler ends of the day; Queensland Health advises against strenuous activity between 11am and 3pm in hot weather.[3]
- Heatwave warnings come from the Bureau of Meteorology, usually from October to March, up to 4 days ahead.[1]
- Confusion, hot dry skin or collapse in hot weather can be heatstroke: call 000 immediately.[4]
How hot does a car get in a Brisbane summer?
Much hotter than the day feels. The Queensland Government says that on a typical Australian summer day, the temperature inside a parked car can be as much as 30 to 40 degrees higher than outside.[2] Steering wheels, seatbelt buckles and dark seats get hot enough to hurt, and anything left inside heats up with them.
That's why the heat advice is so firm on one point. Queensland Health says never to leave children, older people, people with disability or animals in a parked vehicle, even for a short time.[3] If you see a child or animal shut in a hot car and in distress, call 000.
- Don't leave in the car: phones, power banks, aerosol cans, medicines, glasses, chocolate, or anything that melts or can be damaged by heat.
- Do leave in the car: a folding sunshade for the windscreen, and a towel to throw over a hot seat or a child's car seat before anyone sits down.
- Check the back seat every time you lock the car. It's an easy habit, and it's the one that matters most.
How do I cool a hot car quickly?
- Open the doors or windows first for a minute to let the trapped hot air out.
- Start the engine and set the air-con to fresh air (not recirculate), fan on high, with the windows down for the first minute or so of driving.
- Close the windows and switch to recirculate once the air from the vents feels cool.
- Point the vents at your upper body, not just your face.
Park with the sun in mind: point the windscreen away from where the sun will be when you come back to the car, and use shade, or the covered level of a car park, wherever you can. Covered parking also helps in storm season: see hail and your rental car.
If the air-con stops blowing cold, or the car's temperature gauge climbs in traffic, don't ignore it. Pull over somewhere safe and see a warning light came on in your rental car.
Planning a drive on a hot day
- Timing: Queensland Health advises avoiding strenuous activity between 11am and 3pm in hot weather if possible.[3] For a day trip, that means an early start and a long lunch somewhere cool.
- Water: take more than you think you need, for everyone in the car. Queensland Health's general guide is for adults to drink water regularly through the day, even when not thirsty, aiming for about 2 to 3 litres a day unless a doctor has said otherwise.[3]
- Sun: the UV index in Queensland is high enough to damage skin all year round.[2] Sunscreen, sunglasses and a hat help on any trip with stops outdoors.
- The car: before a longer drive, the Queensland Government's checks include tyres at the right pressure, coolant and other fluid levels, coolant hoses that don't leak, and the battery.[5] Our terms ask you to check oil, water and tyre pressures on long trips.
- Fuel: fill up before you leave the city. Sitting in a queue with the air-con on and the fuel light flashing is no way to spend a hot afternoon.
If the car does stop on a hot day, you may be waiting a while. Keep water and a hat in the car, and see breakdown, flat tyre or warning light for what to do. Summer also brings storms and wildlife on country roads at dusk: see kangaroos on the road at night.
How will I know a heatwave is coming?
The Bureau of Meteorology describes a heatwave as maximum and minimum temperatures that are unusually hot over 3 days, compared with the local climate and recent weather. It rates them as low-intensity (frequent in summer and manageable for most people), severe (less frequent, and harder for vulnerable people) or extreme (rare, and a risk even to healthy people who don't take precautions).[1]
Heatwave warnings are issued for severe or extreme heatwaves forecast within the next 4 days. Forecasts and warnings usually run from October to March, and can start earlier or finish later. They're on the Bureau's heatwave service and in the BOM Weather app.[1] A severe or extreme warning is a good reason to move a long drive to another day.
Signs of heat illness to watch for on the road
Drivers and passengers can both be affected, so keep an eye on everyone in the car. Queensland Health lists these signs:[4]
| Condition | Signs | What to do |
|---|---|---|
| Heat exhaustion | Pale skin and heavy sweating; worsening tiredness or weakness; fainting or nearly fainting; fast, weak pulse and quick, shallow breathing; nausea or vomiting; worsening headache and dizziness | Stop driving. Move to a cool place, lie down and loosen clothing, cool with wet cloths, and sip cool water. Call 000 if the person becomes unconscious or starts vomiting. |
| Heatstroke | Confusion, poor coordination or slurred speech; hot, dry skin, possibly without sweating; rapid breathing and pulse; vomiting, diarrhoea or loss of consciousness | A medical emergency: call 000 immediately. Cool the person and give small sips of fluid only if they are conscious and able to swallow. |
For advice when symptoms aren't an emergency but don't improve, Queensland Health's 13 HEALTH line (13 43 25 84) connects you to a registered nurse.[3] Anyone who feels dizzy, confused or faint should not drive.
Picking up or leaving a car in summer
Arriving in summer by bus, train or on foot? Getting to Hendra can mean some time in the sun with luggage. If you're coming from the Gold Coast, see Gold Coast Airport to Brisbane, and if you're coming off a ship, see Brisbane International Cruise Terminal to Hendra. If you'll leave the car parked for days, use the sunshade and empty it of anything heat can spoil.
At pickup, ask us to show you the air-con controls before you drive away. If anything isn't working as it should on a hot day, call 0414 427 760. Clause 7.1 of our terms asks you to stop and tell us if a warning light appears.
Sources
- Bureau of Meteorology (updated 6 October 2023): How will I know if a heatwave is coming? (read 5 November 2026)
- Queensland Government (qld.gov.au): Heat and sun safety (read 5 November 2026)
- Queensland Health (qld.gov.au): How to keep cool and stay hydrated (read 5 November 2026)
- Queensland Health (qld.gov.au): Signs and symptoms of heat-related illness (read 5 November 2026)
- Queensland Government (qld.gov.au): Road safety and vehicle maintenance for long trips (read 5 November 2026)
Written by the Rentzy team at Rentzy Car Rentals. Rentzy prices, fees and rules in this guide come from our published terms and update with them; rules set by others (roads, tolls, licences, transport) are from the official pages above, as read on the dates shown. Something out of date? Tell us.
