Transportation · When transportation fails
Summer vehicle risks are different from winter, not smaller. Tire blowouts peak in July. More batteries die from heat than cold. Your kit needs twice the water.
The risks
Peak in summer. Hot pavement plus underinflated tires is the primary cause. Pavement temperatures exceed 150°F on a 95°F day.
Stop-and-go traffic in 100°F heat stresses the cooling system. Low coolant, a weak water pump, or a failing thermostat turns a commute into a breakdown.
Heat degrades battery chemistry faster than cold. The damage accumulates invisibly through summer and surfaces as the first cold-start failure in fall.
A parked car exceeds 140°F inside within 30 minutes. A roadside breakdown without shade or water creates a heat emergency for driver and passengers.
Before May
Check when cold (morning, before driving). Heat adds 1 to 2 PSI per 10°F rise. An already-warm tire reads artificially high. Underinflation is the leading cause of summer blowouts.
Coolant level, hose condition (squeeze the hoses; soft or cracked means replace), and radiator cap seal. The cooling system works hardest in summer. A $15 hose replacement prevents a $1,500 engine repair.
Turn on the AC before the first hot week. Confirm cold air comes out within 2 minutes. A weak or non-functional AC system in a 100°F breakdown is a health risk, not a comfort issue.
If the battery is 3+ years old, test it. Summer heat accelerates wear that winter cold exposes. The test is free at any auto parts store.
Summer storms can be sudden and heavy. Replace blades that streak. UV exposure degrades wiper rubber through winter and spring, so they often need replacement by May.
Remove winter items. Add summer items: extra water (2 gallons total), electrolyte packets, sunscreen, hat, windshield sun shade, light-colored tarp for emergency shade.
If it happens
The numbers
On a 90°F day, a parked car's interior reaches 109°F in 10 minutes, 119°F in 20 minutes, and over 140°F in 30 minutes. Cracking the windows does not meaningfully reduce these temperatures. The greenhouse effect through the glass is the problem, not ventilation.
Children and pets are at the highest risk. A child's body temperature rises 3 to 5 times faster than an adult's. Heatstroke can begin in as little as 15 minutes in a hot vehicle.
For the occupants: if stranded on an exposed shoulder in summer, use the sun shade on the windshield, open all windows, and drape a light-colored sheet or tarp over the sun-facing side of the vehicle. Drink water. Apply sunscreen if you will be outside the vehicle. Move to shade if any is available within safe walking distance.
"The best time to repair the roof is when the sun is shining."
— John F. Kennedy
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