Hospitals and A&E units will be under the cosh in the coming week, as extreme heat hits the same time as planned strikes.
Today marks the third strike for 72 hours by members of the British Medical Association (BMA) regarding pay, which has led to health bosses telling the public to expect large disruption and delays.
The hot weather is projected to have more people fall ill, either with heat stroke, heart failure and respiratory issues.
However, close to half the medical workforce is expected to walk out – leading to huge understaffing and large cancellations of care.
The previous walkout in April saw more than 196,000 hospital appointments cancelled.
NHS England Medical Director Stephen Powis said: “The NHS is facing significant disruption this week, with a three-day strike that is set to be exacerbated by the ongoing hot weather. Emergency, urgent and critical care will be prioritised this week but some patients will unfortunately have had their appointments postponed – if you haven’t been contacted to reschedule, please do continue to attend your planned appointment.
“As ever, use 999 and A&E for life-threatening emergencies – and NHS 111 online for all other health conditions,” he added.
Explaining the strike, Dr Vivek Trivedi, Junior Doctor Leader at the BMA, said: “Junior doctors are in despair at this government’s refusal to listen. We have made clear that junior doctors are looking for the full restoration of our pay. The NHS can only function with a workforce that is properly valued.”
Last month the government offered a 5% increase, which was rejected.
Temperatures are peaking across the UK into the high 20s and low 30s, which has already led to a strain on resources, the NHS Confederation has said.