British champion, Paula Radcliffe, has given her top tips for running the London Marathon in the scorching weather.
Sunday's race is set to be the warmest on record with temperatures expected to hit 23 degrees Celsius.
Speaking to ITV News she highlighted hydration and pacing as key to staying safe while running the 26.2 mile route.
So what exactly does the champion suggest for the 39,000 people facing the marathon start line this weekend?
Make sure that you hydrate beforehand.
Fuel well before race day.
During the race drink water before you think you need it.
Use Vaseline and anti-chaffing particularly on your feet.
Take advantage of the water on the course and tip it over you.
Run in the shade when you can.
Adjust your pace goals when you can.
Listen to your body.