More than 100 Greater Manchester firefighters continue to tackle seven pockets of fire in an area spanning up to 6km across Tameside.
--> READ MORE: Homes evacuated as Saddleworth Moor fire declared a 'major incident'Problems faced by the crews included frequent changes in wind direction, the peat-embedded terrain which requires large quantites of water to extinguish flames and the searing temperatures.
An RAF Chinook helicopter is likely to be deployed to provide the military with the assistance requested, said Greater Manchester Fire and Rescue Service (GMFRS).
Dave Keelan, director of emergency response at GMFRS, said: "The request is to assist us to move some high volume pumps by air to locations that we couldn't get them to with vehicles, and also the ability to transport personnel to those more remote areas so we can get there quicker with more people with the water supplies we hope to put in place to try and resolve the incident in a quicker nature.
"We are still in detailed discussions with the miitary over the logisitical element of it. They will obviously move as quick as they can to get resources here."
He said transporting two of the high volume pumps to remote locations would give his crews an "excellent quantity of water with a nice main across a big area that we can tap into".
Mr Keelan said firefighters were working "extremely hard in really hot conditions" but morale was high as he said: "It's more of a task to get them down here to rest."
As of Wednesday lunchtime there were seven separate fire incidents ongoing on areas of the moors, including Calico Crescent, Intake Cottage, Intake Lane, Caste Farm, Dovestones, Higher Swineshaw and Chew Road.
Firefighters on a total of 29 fire engines from Greater Manchester and neighbouring fire and rescue services used beaters and specialist wildfire equipment to tackle the flames.
In addition, Greater Manchester Police deployed a helicopter to assess the scene and United Utilities provided a helicopter that can be used to drop water onto remote areas.
The blaze, on the edge of Saddleworth Moor, started on Sunday and was brought under control but it reignited the next day and has continued in one of the worst moorland fires to hit the region.
The impact of the blaze could even be seen from space as Nasa satellites picked up the plumes of smoke.
Among the affected areas was the village of Carrbrook, in Stalybridge, where 34 households in the Calico Crescent area were evacuated on Tuesday night when strong winds pushed flames near to their properties.
Householders were allowed to return home on Wednesday following air quality assessments.
Air quality levels in the area are being monitored regularly in different locations with people in affected areas urged to follow advice from Public Health England and keep their windows and doors closed.
Experts warned that high levels of pollutants generated from the blaze could have a significant effect on people's health.
Hugh Coe, professor of atmospheric composition at the University of Manchester, said plume peak concentrations were "very high" and air quality close to the fire was "very poor".
He said pollution plumes have been detected in the centre of Manchester.
Four local schools decided to close on Wednesday for the safety of their pupils.
Brenda Warrington, leader of Tameside Borough Council, said: "We have no idea how long this situation will continue because it's the weather conditions that will determine that and will dictate to us.
"One of the things we need, and I don't usually ask for this in this kind of weather, is a really, really good downpour, sustained for quite some time."
No rain is forecast for Tameside for the rest of the week at least.
The cause of the original seat of the fire - thought to be at Buckton Hill, which is land above Buckton Vale, Carrbrook - has not been established but fire chiefs said a detailed investigation would be launched at the appropriate time.
One possible line of inquiry could focus on the frequent gathering of off-road bikers - many not displaying registered plates - at a nearby large quarry.