Vehicle Heat Safety in Extreme Temperatures

Vehicles are among the most dangerous heat environments during a heatwave. A car parked in the sun with windows closed becomes an oven — reaching internal temperatures that can kill a child or pet within minutes, cause incapacitation in an adult, and damage electronics, medications, and supplies stored inside.

Why Vehicles Are Extremely Dangerous in Heat

A vehicle's interior heats far faster than the outside air because of the greenhouse effect: sunlight passes through windows and heats interior surfaces, which then radiate heat as infrared radiation that cannot escape back through the glass.

Outside Temperature	Inside Car After 10 min	Inside Car After 30 min	Inside Car After 1 hour
22°C (72°F)	32°C (90°F)	42°C (107°F)	47°C (117°F)
32°C (90°F)	43°C (109°F)	53°C (127°F)	58°C (136°F)
38°C (100°F)	49°C (120°F)	60°C (140°F)	65°C (150°F)

Human core body temperature reaches a life-threatening level at 40°C (104°F). A child's core temperature rises three to five times faster than an adult's. Cracking windows open only marginally reduces interior temperatures.

Preventing Hot Car Deaths — Children and Pets

⚠️ Every year, dozens of children and hundreds of pets die from heatstroke after being left in parked vehicles. The majority of cases involve caregivers who did not intend to leave the child — they simply forgot, often due to a change in routine. This can happen to any parent or carer.

Prevention Strategies

1. Never leave a child or pet in a parked vehicle, even for a few minutes, even with windows cracked, even in moderate temperatures.
2. Create a reminder habit — put your phone, wallet, or work bag in the back seat to force you to check the back seat before locking.
3. Keep vehicles locked at all times even when parked at home — children can enter vehicles and become trapped.
4. Ask childcare providers to call immediately if a child does not arrive as expected.
5. If you see a child or pet alone in a hot car, call emergency services (000/911/112) immediately.

If You Find a Child in a Hot Car

1. Call emergency services immediately.
2. If the child is unresponsive or in distress, break a window away from the child (use a pointed object at the window corner).
3. Remove the child from the vehicle.
4. Cool the child rapidly with cool (not ice cold) water, focusing on the head, neck, armpits, and groin.
5. Do not leave to get help — have a bystander call while you act.

Driving in Extreme Heat

Before You Drive

1. Park in shade where possible to reduce pre-heat inside the car.
2. Ventilate before entering — open all doors for 30 seconds to vent hot air before getting in.
3. Use a windshield sunshade when parked — can reduce interior temperature by 10–15°C.
4. Cool the car first — run A/C with windows open for a minute before closing and recirculating.
5. Check tyre pressure — tyres expand in heat; overinflated tyres are at risk of blowout.
6. Check coolant level — heat stress on engines increases cooling system demand.

During the Drive

Strategy	Benefit
Run A/C in recirculation mode	Faster cooling; doesn't draw in hot outside air
Keep windows slightly open with A/C	Improves air exchange; prevents buildup
Keep drinking water accessible	Hydration; drivers lose concentration when dehydrated
Avoid peak heat hours (10am–4pm)	Hottest road temperatures; highest blowout risk
Watch tyre temperature on long drives	Excessive tyre heat precedes blowout

Breakdown in Extreme Heat

A breakdown during extreme heat is a serious emergency, especially in remote or exposed locations.

Steps to Take

1. Signal distress — hazard lights on, hood up.
2. Stay in the vehicle if shade and A/C were recently running — vehicle is still cooler than outside air in direct sun initially.
3. Move to shade if available (overpass, roadside trees) — even small shade reduces radiant heat significantly.
4. Ventilate the vehicle — open windows on both sides to create cross-ventilation.
5. Call for assistance immediately — do not wait to see if the vehicle can be restarted.
6. Conserve water — if you have limited water, drink small amounts regularly rather than large amounts infrequently.
7. If help is delayed, signal passing vehicles using hazard lights, reflective triangles, or arm signals.
8. Do not walk along highway in extreme heat unless shelter is definitively visible — sun exposure and radiant heat from pavement significantly increase heat illness risk.

⚠️ Road surfaces in direct sun can reach 60–70°C (140–160°F). Walking without footwear on hot pavement can cause serious burns within seconds.

Storing Medications and Supplies in Hot Vehicles

Heat damages many common medications. Never leave the following in a hot car:

Item	Heat Effect
Insulin and other biologics	Degraded by heat >30°C; may lose effectiveness entirely
Asthma inhalers and aerosols	Pressurised containers can explode; medication degrades
Sunscreen	Formulation degrades, reducing SPF
EpiPen (epinephrine)	Effectiveness reduced by sustained heat
Eye drops and liquid medications	Chemical stability affected
Electronic devices	Batteries can swell or fail; screens damaged
Emergency snacks	Chocolate, certain bars, soft foods melt and spoil

When travelling with medications in heat, use an insulated bag with a frozen ice pack. Replace the ice pack as needed.

Emergency Cooling Kit for Your Vehicle

Pack the following for travel during extreme heat events:

1. Minimum 4 litres of water per person per day (more in extreme heat)
2. Cooling towels (reusable evaporative cooling fabric)
3. Battery-powered portable fan
4. Emergency foil blanket (reflects radiant heat when used as a shade)
5. Insulated bag for medications
6. Charged power bank for phone
7. Emergency contact list and out-of-area contact number

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Quick Reference

Situation	Action
Child/pet left in car	Call 000/911 immediately; break window if unresponsive
Overheating before entering car	Open all doors, vent 30 seconds, then cool with A/C
Breakdown in heat	Stay with vehicle, signal, call for help, conserve water
Walking in extreme heat	Only if absolutely necessary; stay in shade; avoid hot pavement
Medications in hot car	Never leave — use insulated bag with ice packs
Tyre blowout risk	Check pressure before driving; slow if vibration felt