A yellow alert indicates that weather conditions could pose a risk to those who are particularly vulnerable.
The trust said it traditionally saw a rise in demand during these times, which also might see some patients waiting longer for a response.
Medical director, Dr Chris Grant, said: “Heatwaves can pose significant health risks, especially for the elderly and those with pre-existing medical conditions.
“We encourage everyone to take necessary precautions to stay safe, such as staying hydrated, avoiding strenuous activities during the hottest part of the day, and keeping an eye on vulnerable individuals.
“If you or someone you know shows signs of heat-related illness, seek medical help immediately. By taking these steps, you help ensure emergency services can focus on the most critical cases.”
