As France sizzles under the heatwave, a video has gone viral of a man on the rooftop of a Paris apartment cooking a crêpe using only the power of the sun.

The old 'hot enough to fry an egg' got a distinctly French twist this week, when a Frenchman in Paris demonstrated how his rooftop was hot enough to cook a crêpe.

In an Instagram video that has swiftly gone viral, he explains that he left a frying pan outside on the rooftop for around 20 minutes - he then brings it inside, adds a little butter and cooks a perfect crêpe in the red-hot pan.

But the light-hearted 'crêpe canicule' (heatwave pancake) video from comedian Olivier Giraud also highlights a serious truth about Paris apartments.

The video is instantly recognisable as Paris, partly because the Eiffel Tower is in the background, but also because of the zinc rooftop that the crêpe pan is resting on.