There is one habit we all have: before going out, perfume on the neck and the wrists. In January that is harmless. In July, if you then sit in the sun, it is a recipe for marks that will stay on your skin longer than the summer does.

The problem is not the perfume, it is what is underneath it

Silvia Spera, a perfume expert, says it without hedging: do not apply it directly to skin that will be exposed to the sun, because alcohol and certain ingredients can cause photosensitisation marks.

The mechanism is simple. Some aromatic molecules and alcohol make the skin more receptive to ultraviolet radiation. The point where you sprayed the perfume - the neck, the wrist, the décolletage - is exactly where the sun hits hardest. The result is a darker patch in that spot, which then takes months to fade.

A solution that does not ask you to give anything up

Spray onto clothing, not onto exposed skin. Fabric holds the scent longer than skin does and does not react to sunlight. If you still want skin, go for the places that stay in shade - the inner wrist under a sleeve, the neck under your hair.

The second rule is concentration. Summer does not call for eau de parfum but eau de toilette - lighter, quicker to evaporate, better suited to a temperature at which any heavy scent becomes unbearable after two hours.

What works at 35 degrees and what does not

Spera recommends fresh, light notes: eucalyptus with its green freshness, geranium that recalls rose with a menthol edge, ginger giving a spicy-citrus tone. The same group includes cardamom, white musks, bergamot, lime and marine notes.

What does not work is predictable: amber, vanilla and oud. Those are winter scents - in the heat they turn heavy and instead of a trail they leave a cloud.

Mists: less perfume, more sense

The summer favourite are water-based sprays. Angel Fernandez of Armani Beauty explains the technique: you create a small cloud around yourself, spray in a circle, and let the mist settle onto skin, hair and clothes.

The advantage is not only freshness. They are cheaper than classic perfumes, easier to carry in a bag, and can be reapplied throughout the day. The prices quoted on the Spanish market run between 29 and 59 euros.

This whole story comes down to one thing: summer does not ask you to give up scent, it asks you to stop wearing it the way you do in November. That is a cheaper correction than any dark-spot cream you will be looking for in September.