Air conditioning: the silent killer? We used to have 'ARKO': All Windows Can Open.
The Thermador Car Cooler was an intermediate solution
But in the meantime, a not insignificant part of the classic fleet also has air conditioning and we can handle any temperature while smiling. If the air conditioning is okay at least.
And it wants to be missing that. Many car owners think that an air conditioning system is maintenance-free. That's not it.
That 'being fine' also means that the air-conditioning system is clean. Free from dust, dirt bacteria and fungi.
The dust and deposits have been left there: an air conditioning system works with changing temperatures in a generally humid environment. And that is precisely where the environment is bacteria and fungi feel the best.
In this way the air conditioning can become a true incubator of health-threatening micro-organisms.
And all those little woes are brought into the interior by the airflow from the ventilation system.
Working with deodorants and disinfectant sprays from the car shop? That is usually symptom control. However, there are disinfectant sprays.
Fungi and bacterial control can also be done effectively with ozone or ion equipment. ( www.lamersequipment.nl) The better car cleaning companies usually have those (quite expensive) equipment, if only because of the odor-eliminating properties.
A car treated with ions or ozone even smells clean 
if he has been a lover of wet labradors smoking a cigar.
To eliminate that source of possible misery, it makes sense to have an air conditioning system checked once a year.
Because a car that leaves you with watery eyes and a scraping cough?
Don't you want that?