Fridge maker Beko is urging customers to slip a piece of A4 paper into their fridge this week while the weather is still hot.

The common letter-sized paper used in Europe and in most locations outside of North America. At 8.3 x 11.7" (210x297mm), A4 paper is slightly narrower and a little longer than "A" size 8.5 x 11 ...

Step 1: Get an A4 piece of paper, origami paper can help make things easier, but it's not essential. Fold the bottom left corner over to the top right corner, making a pointed triangular shape.

And a computer simulation also suggests that punctures in the hull the size of A4 pieces of paper led to the ship's demise.