A investigation has been launched by the Fire Brigade Union after a dehydrated firefighter was taken to hospital from the scene of a Gants Hill blaze.

The 47-year-old man was reportedly “aggravated and ill” when colleagues stripped him of his gear and called in paramedics.

Union sources say 30 firefighters who spent two-and-a-half hours battling the blaze in Woodford Avenue last week, were provided with a few 500ml bottles of water, and a request for back-up supplies was turned down.

But the London Fire Brigade has told the Recorder there was no shortage of drinking water.

Appliances are issued with a filter which can be attached to a fire hydrant in order to provide crews with water at incidents.

The spokesman said: “This means all our firefighters, who are all issued with refillable water bottles, have an easily accessible and continuous supply of fresh drinking water.”

He added there were five hydrants in the immediate area.

But sources – who have not given their names to protect their jobs – claim attaching water filtration equipment to a nearby hydrant was “operationally impossible” given the distance of the nearest available fire hydrant.

The source added: “It was a very intense fire and everyone was struggling. The gear we have to wear is like a boil in the bag suit – you just don’t cool down.”

A woman is still understood to be in hospital with serious spinal injuries after plunging two floors from her burning flat.

The woman, named locally as Jenny Noor, jumped from the blaze above Crossland Estate Agents moments after her husband, Shah Noor – who was also seriously hurt.

Heroic bystanders helped save a third woman from serious injury by holding out a dust sheet for her to jump into.