Top top-ups! Here are my favourite products for on-the-go sunscreen

Imagine you’re attending a summer wedding or sports day, or just planning a trip to the park or beer garden. You have slathered on a generous layer of SPF and feel smugly well prepped against sunburn and premature ageing.

What you may not realise is that you’re good only for the next two hours. Depending on which study you believe – from the US’s Johns Hopkins medical school to the NHS – sunscreen should be reapplied every 120-180 minutes if it is to continue to be effective. As with much medical advice (your five-a-day fruit and vegetables, for one), this rule is scientifically sound – but is it remotely likely that people are going follow it to the letter?

It’s one thing to keep layering on the SPF when you’re lying on a remote beach, but quite another to bother doing it on home soil when wearing proper clothes and carefully applied makeup. This is why, as a committed but always pragmatic sunscreen wearer, I start with lotion and pack an invisible touch-free SPF for over-makeup top-ups.

My favourite is Ambre Solaire sensitive hydrating face sun cream mist, a mere £6.50. I know I’ve mentioned it previously, but it bears repeating because it remains the best, most bargainous and indispensable product any makeup-wearing person could buy.

It mists imperceptibly over even a full face of makeup, adding a veil of hyaluronic acid-laden hydration, and an SPF of 50. The small aluminium can also fits into a smallish handbag, so one need never compromise on safety for the sake of convenience.

For oily skins, La Roche Posay’s Anthelios anti-shine sun protection invisible SPF50+ face mist, at £14, is the same brilliant idea but leaves a more matte finish (there’s also a kids’ version). This can obviously be used for the whole family, but it also makes the ideal choice for adults with sensitive skins. Anyone with easily irritated skin should head to the children’s aisle in general.

Related: We should wear sunscreen year-round: if that’s too hard, try an SPF moisturiser | Sali Hughes

Newer to the market is (Re)Setting 100% mineral powder SPF30 PA+++, £28, by terrific suncare brand Supergoop! (not to be confused with Gwyneth Paltrow’s wellness empire). Unlike the others, this is a loose, twist-up, non-irritating face powder that can be fluffed on generously and regularly over your base layer sunscreen and makeup.

I had been expecting it to look rather dusty and cakey as the day wore on, but it stayed light and fresh – and doubled successfully as a mattifier on a sweaty nose.