Cruises: Never book THIS popular activity onboard the ship during your holiday

Teeth whitening, no matter how expensive or professional, often leaves the teeth aching for a few days after.

This is because of the peroxide used in the gels to brighten them.

It can strip the top layers of the teeth off, meaning food such as ice-cream and hot meals can cause a lot of pain.

The pain does, however, wear away after a few days.

Teeth whitening isn’t the only thing to be avoided on the first day of a cruise holiday.