Desk sheet - Interior
Two Pieces of Hot Weather Advice, and Only One of Them Survives a Month
Both are sensible for an afternoon at a shopping center. Over three weeks in a parking lot one of them keeps working and the other turns into a liability, and the difference is worth two minutes of reading before you leave.
01The one that works: a folding shade behind the glass
A reflective folding shade across the inside of the windshield does exactly one thing well, and it happens to be the thing that matters most: it keeps direct sun off the top of the dashboard, which is the hottest and most vulnerable surface in the vehicle.
Over a month between May and September that is worth having. It is cheap, it takes ten seconds, and it addresses the part of the car that the heat sheet identifies as taking the damage.
Two honest caveats.
It does not cool the cabin. The car will still be very hot when you open it. A shade protects a surface; it does not deliver you a comfortable interior on the day.
It is not a substitute for a canopy on a long stay. A shade covers the windshield. A canopy covers everything, including the rear glass, the roof and whatever is on the parcel shelf.
02The one that does not: leaving the windows cracked
The advice is that an inch of open window lets heat escape and keeps the interior cooler. For an hour in a supermarket parking lot, that is broadly true and harmless.
For three weeks in a lot near Tucson it fails on three separate counts, and any one of them is enough.
| What a cracked window lets in | Over an afternoon | Over three weeks |
|---|---|---|
| Dust | A little | A film on every interior surface, and grit in the seals |
| Water, during a monsoon burst | Nothing, usually | One hard hour is enough to wet a seat |
| Small desert animals | Very unlikely | The single easiest way in, and the reason this matters here more than elsewhere |
| Heat, going out | Some benefit | Almost none, because the car reheats every morning anyway |
The third row is the one specific to this place. The sheet on the engine bay sets out why a standing car is interesting to small animals; a gap in the glass turns the cabin into the same kind of shelter as the engine bay.
And note what the fourth row says, because it is the part that undermines the original advice on its own terms: the heat benefit is real for the first hour and irrelevant over weeks, because the vehicle is reheated from scratch every single day.
03The short list of what is actually worth doing
- Set the tire pressures and note the date. See the pressure sheet.
- Put a folding shade behind the windshield, if the stay is a week or more between May and September.
- Close every window completely.
- Take everything edible out, including whatever is in the trunk.
- Take the parking ticket, the gate code and the operator's number with you, not left in the car.
That is the whole preparation list, and nothing on it needs anybody's help.
04What we do not do
None of the above is done for you. Nothing is placed inside a vehicle, no shade is fitted, no window is closed on your behalf and nothing is removed. It is one of the five refusals, and this is the sheet where the reason is clearest: the inside of your car is not somewhere anybody else should be.
You keep your keys, so nobody could do it anyway. That is by design.
05What this means for the reservation you should make
The advice above does not change which band or grade you should book. What it changes is the ten minutes before you hand nothing to anybody and walk to the van.
The one connection to the reservation: if the stay is long enough that a shade matters, it is long enough that a shaded stall is worth asking about, and the two work together rather than replacing each other.