The North East Ambulance Service says it is receiving what it describes as an 'unprecedented' number of calls which is putting pressure on the system.
It says that on Saturday 17 July, call handlers took 140 more 999 inquiries than on the same day the previous week.
As well as responding to 999 calls, NEAS is responsible for the non-emergency 111 service.
Clinical Services Manager Claire Jobling says teams have been receiving inquiries about sunburn and sunstroke, as well as queries about the COVID vaccination.
She is urging people to keep 999 lines free for patients with life threatening situations.
The service is also asking the public for understanding towards its teams on the road, remembering that they are working in hot conditions wearing PPE.
The surge in demand comes as NEAS gears up for the end to COVID restrictions on Monday 19th July.
It says it doesn't want to stand in the way of people enjoying the summer, but is urging everyone to think about their behaviour and its impact on others.
Ambulance crews aren't the only emergency service experiencing a high volume of calls.
Northumbria Police have also urged members of the public to only call 999 in the event of an emergency which requires an urgent police response.
In a tweet, the force directed members of the public to their website to answer questions which do not demand urgent help.
The number of 999 calls made to emergency services often spikes during good weather.
There is a plea from first responders for everyone to act responsibly as the final lockdown measures are lifted on Monday 19 July, as part of the government's 'roadmap out of lockdown'.