Hospital wards, care homes and offices are regularly topping 30 degrees celsius with staff trying to deliver care without access to air conditioning, fans or even windows that open, the nursing union said.

RCN general secretary and chief executive, Professor Nicola Ranger, said: ‘These testimonies should be a wake up call. When nursing staff are collapsing, feeling dizzy, sick or even being admitted to the very hospitals they work in because their workplaces cannot handle the heat, it shows just how badly they are being failed.'

The RCN's comments came after health secretary Yvette Cooper warned the NHS will have to prepare for annual summer heatwaves in addition to winter pressures, while the Government's Climate Change Committee in May called for all hospitals and care homes to have air conditioning within the next decade. 

The nursing union called for the Capital Guidance, which sets the rules and limits for spending on estates and is issued by NHS England to trusts, to be updated to include adaptations to climate change. 

The RCN is also demanding the Government reduce emissions and play a leading role on the global stage in the fight against global warming and introduce a proper plan to reduce emissions produced by health and care services.