Here I am in a trouser suit with a Hawaiian shirt. It’s a Monday-morning look.’

This summer, your short-sleeve shirt is getting called up for early service

Right, it’s time to start wearing your summer clothes. There is, after all, no point waiting around for summer, which may arrive at any point between next week and August, and may last anywhere between three months like last year *prays* or a weekend.

To clarify, what I mean by summer clothes is anything that isn’t coats, jumpers and tights. I’m not suggesting you strip off to strapless sundresses and dig out your cut-off denim shorts. But a good chunk of your summer wardrobe can come into active service immediately.

Even better, there is a specific category of your summer wardrobe that can be called up to be a new look for spring. This week’s edition of Old Clothes For A New Look starts with a short-sleeve shirt. I bet you’ve got one, somewhere. What would you wear if you were, say, going sightseeing? Or to someone else’s barbecue? Yes, that shirt! This season, you can repurpose that shirt and make it look slick. It may have a garish print, or be a bright colour, or in broderie anglaise, or have some other feature that seems to pigeonhole it as a high-days-and-holidays shirt. But this summer, your short-sleeve shirt is getting called up for early service.

At this spring’s Paris fashion week collections, Kaia Gerber wore a boxy white shirt with CHA and NEL printed across the pockets, teamed with red lipstick and smart black trousers. At Balenciaga, a stiff and shiny short-sleeve shirt was tucked into a mini skirt and worn with high-heeled sandals and major earrings. At Fendi in Milan, Bella Hadid wore a crisp beige short-sleeve shirt, buttoned to the throat, with a smart boxy handbag and court shoes. (That she wore this with cycling shorts need not concern us here. She is Bella Hadid.) The point is that a short-sleeve shirt is smart, this summer.

Here I am in a trouser suit with a Hawaiian shirt. It’s a Monday-morning look, with an out-of-office spirit. No bad thing, on an Monday morning. It’s kind of an update on the trouser suit with a slogan T-shirt look of last year. I am slightly cheating on the rules of this column because this shirt isn’t, strictly speaking, from my wardrobe. It belongs to my 16-year-old son. But he won’t miss it – at least, not until he reads this (Hi, Alfie!). Because it’s not summer, and who wears short-sleeve shirts in March? I do. And so do you, now.

• Shirt, Jess’s son’s own. Green blazer, £89.99, and trousers, £39.99, both zara.com. Red heels, £69, office.co.uk