When I was growing up, summer heatwaves were a joy – an all-too-rare opportunity for the people of Britain to dig out the shorts, barbecues and paddling pools and suspend some of the normal conventions of life.  Yes, there were problems – water shortages, buckled train tracks – but we all knew it would be brief and that we'd be plunged back into the usual gloom and drizzle before too long.

The message now is slightly different.  More frequent bouts of excess heat join excess rainfall as signs that our climate is changing, and whereas once we would have put up with temporary disruption, we now realise our infrastructure isn't equipped to cope.  Poorly insulated homes, poorly ventilated offices, leaky reservoirs and antiquated sewerage systems all mean that extreme weather causes real hardship and dangers to health.  We also know the impacts are felt first and worst by those in society who have least protection and least choice.  Those people and places already experiencing the most significant health inequalities are the same people and places to be impacted by environmental harms.