The historic match in County Durham is likely to be known forever as the Hot Spot Test. Considering that the previous four Test matches at the ground have required thermal underwear and two overcoats to be sure of watching in anything approaching comfort, this may be something of a misnomer.
It refers, of course, less to the climate, though that is pleasantly temperate at present, than to the gizmo that has dominated the Ashes series. Hot Spot, the thermal imaging system which shows a mark if the ball hits the bat – no escaping thermals in some form or other in this neck of the woods – was spared after both sides met the International Cricket Council.
Speculation was rife that while the Decision Review System would stay, the Hot Spot element of it might be abandoned for the rest of this series given the controversy it has caused so far. Not only has it been inconsistent, not only have third umpires appeared to interpret the presence or absence of marks in different ways, but it was also sensationally, if misguidedly, claimed two days ago that players on both sides were using silicone tape round the bat to negate its effect. Poor Kevin Pietersen was the only one to have allegedly used it to be named.
With all those elements still in play, attention is bound to be directed at Hot Spot's use, purpose and proficiency throughout the match. Every possible nick, edge or faint touch will be played and replayed. Technology, whether the ICC likes it or not, is on trial again.
It is a pity that it is distracting from a riveting contest. England might have retained the Ashes by escaping with a draw from Old Trafford last Monday when it bucketed down with Australia rampant, but their opponents have now injected their self-belief with genuine substance. There is, as both captains are plainly aware, plenty of cricket still to be played in the next two matches.
England have won all four previous Tests at the ground against opponents who froze. Rarely has that term been applied literally in sport, except perhaps husky racing. Australia are in a different league in a different time of the year.
There will be mild debate for both countries about the composition of their starting XIs. The home side will probably be unchanged, preferring to offer another go to the men who almost mucked it up in Manchester.
Equally, they will remember that they were prepared to change a winning side after the first Test at Trent Bridge and were immediately rewarded with a thumping 347-run victory at Lord's which enabled them to go 2-0 up in the series and put them in the happy position they now occupy. There will never be a more appropriate moment to pick Graham Onions.
He is in form, he would be playing at his home venue where he knows every blade of grass and would be bound to receive fervent vocal backing from the North-east crowd.
It is a ground that traditionally has helped seam bowling. Of the 80 wickets that England have taken in Tests here only nine have been to spin and five of those were in one innings for Monty Panesar in 2007.
Not that England will remotely contemplate going into the match without their off-spinner, Graeme Swann. The pitch is much too dry, he is the series' leading wicket-taker and all sorts of records beckon for him in the next fortnight.
Onions is unfortunate not to have played more than nine Test matches. While the case is powerful for him to play in this match, the general perception that his sustained effectiveness is because of bowling at Chester-le-Street (rather like batting at Taunton) is incorrect.
He has 183 wickets at home at 25.78, and 195 away at 25.49, all but identical. He is simply a splendid bowler, but for all that Stuart Broad has taken only six wickets in the three matches so far, it would be beyond rotation to leave him out now.
Australia would dearly like to keep the same team. There are flaws in several places but also the first indications of green shoots of recovery among the batsmen. Still, only Michael Clarke and Matthew Wade have scored hundreds in the eight Tests they have played this year. And Wade is in the squad but will not be in the team because he has been relegated to the role of secondary wicketkeeper.
The place under most discussion will be that of Ryan Harris, their most potent bowler so far with 11 wickets in the two matches he has played. He has looked dangerous in every spell he has bowled. He is fast, skiddy and moves the ball both ways but he has a body that tends to show the strain being put on it by breaking down.
England's recently fitful upper order has not come off well against Harris and he has dismissed Jonathan Trott three times in four innings.
Generally, England need to be in much better positions than the 102-3, 121-3 (after being 11-2), 28-3, 30-3, 64-3, 27-3 in which they have so far found themselves.
Hot Spot may determine the fate of both sides. The ICC was doubtless relieved that both sides gave Hot Spot and DRS their backing after meeting with its cricket general manager, Geoff Allardice. As Allardice said: "It is conclusive – when there is a mark we know the bat has hit the ball. Or indeed the pad when lbws are being determined, which may save some batsmen occasionally."
Alastair Cook, England's captain, was at a loss to understand why it has been so imperfect in this series. "Everyone's made quite a big deal of the Hot Spot stuff," he said. "But there have been a couple of human errors from the third umpire, which the ICC have mentioned."
Both Cook and his counterpart, Clarke, are annoyed and fed up by the allegations about using silicone tape as a masking device.
Channel 9, who broke the story in Australia, has yet to provide supporting evidence. England have demanded an apology. "I think an apology is due because it's such a blatant fabrication," said Cook. Hot Spot has never had a bigger Test.
Fourth Ashes Test: urham details
England A N Cook (capt), J E Root, I J L Trott, K P Pietersen, I R Bell, J M Bairstow, M J Prior (wk), G P Swann, S C J Broad, J M Anderson, T T Bresnan.
Australia M J Clarke (capt), S R Watson, C J L Rogers, U T Khawaja, S P D Smith, D A Warner, B J Haddin (wk), P W Siddle, R J Harris, M A Starc, N M Lyon.
Umpires A Dar (Pak) & T Hill (NZ).
Pitch report Dry, likely to break up early and offer something to all bowlers. Unlikely that totals of 500 will be scored.
Weather Staying mainly dry today, with regular spells of sunshine. Small chance of rain in the afternoon. Maximum temperature: 21C
Odds England Evens; Draw 5-2; Australia 11-4.
TV Sky Sports Ashes, 10am-7pm. Highlights Channel 5, 7-8pm.
The series so far
First Test (Trent Bridge) England won by 14 runs
Second (Lord's) England won by 347 runs
Third (Old Trafford) Match drawn
Fifth (The Oval) 21-25 August