London Marathon runners warned to ‘think carefully’ about wearing heavy costumes as race to be hottest in history

London Marathon organisers have warned runners to “think carefully” about wearing bulky and heavy costumes for the race, which is set to be the hottest in its history.

Previous marathons have seen runners attempt the 26.2-mile course clad in 66 lb bomb disposal suits, dressed as deep sea divers and carrying a fridge.

However the unseasonal mini heatwave Britain is experiencing is making this April one of the hottest on record and seen highs of 26C in the South East.

The Met Office is currently forecasting temperatures of  up to 23C in London on Sunday.

The warmest conditions the London Marathon, which was founded in 1981, has been run in was 22.2C in 1996 and 2007.

Hugh Brasher, Event Director of the 2018 Virgin Money London Marathon, said runners should reassess their goals and costumes in light of the hot conditions.

He said: “Most importantly, runners should adjust their goal for Sunday and plan to run at a slower pace.

“If they were planning to run in fancy dress, they should think carefully if that is appropriate in the forecast conditions.”

On Thursday London Marathon organisers sent new advice to runners on how to cope with the hot weather.

Its advice on what to wear said runners should opt for “lightweight moisture management clothing designed for use in warmer conditions”.

The event's organisers are currently putting in place contingency plans for the hot weather including increasing the number of drinks stations and providing extra water for runners to douse themselves.

They are also setting up more showers to help runners cool off and stocking first aid stations with extra ice.

Save the Rhino, the charity behind the iconic rhino outfit which is an annual fixture at the race, is also cautioning its runners to not over exert themselves during the marathon.

It warned that it is already “very humid” inside the rhino suits and said this year it would be providing a station at mile 22 with extra water and Vaseline.

Its advice to runners said: “If you are feeling the heat getting to you please do slow down, the conditions are not ideal for a PB (personal best) so please don’t push yourself to do so and risk your health, take it easy and enjoy the party atmosphere.”

The rhino suits were originally made in 1989 for a musical named Born Again before being donated to the charity.

They made their debut at the London Marathon in 1992 and the charity has a waiting list ever year of runners wanting to attempt the race in the 17lb suit.

The Charity said it usually has around 17 runners wearing the rhino costume at the London Marathon.