Sunday’s meeting at Stratford has been brought forward by two hours due to the extreme heat warning, the British Horseracing Authority has confirmed.
The card was due to get under way at 1.57pm and conclude at 5.23pm, but it will now begin at noon and finish at 3.05pm.
There are no plans to make any changes to the timings at Newton Abbot and Redcar, Sunday's other meetings.
BHA Veterinary Officer Sally Taylor said: "Whilst we are confident that it is safe to race in higher temperatures, we want to ensure that conditions are as comfortable as possible for our horses and people. We have therefore taken proactive steps towards changing the race day with that in mind.
"Having considered the local weather forecasts and other significant temperature factors for other courses due to race over the coming days, we do not feel that similar adjustments will be necessary everywhere.
"However, all the usual hot weather provisions will be in place at all courses, with sufficient cooling facilities and regular monitoring throughout the day to help ensure the safety of our equine and human participants."
The BHA will monitor forecasts for the coming days and further updates will be issued in due course.
