Root's incredible display of courage amid health scare

Joe Root's nightmare maiden Ashes tour as captain ended in bouts of dehydration, diarrhoea and vomiting in the SCG dressing rooms.

Root did not return to continue his innings after lunch on day five in Sydney, as the visitors fell to a 4-0 series scoreline with an innings-and-123-run defeat on Monday.

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Hospitalised after Sunday's record-breaking Sydney heat, Root did not resume his innings at the start of play on Monday but came out after Moeen Ali was dismissed midway through the morning.

Symptoms returned when he went to lunch at 58 though, ending his series as Australia's quicks ran through England's tail.

The 27-year-old was then too unwell to participate in the on-field presentation.

Root spent the most time of all players in the middle on Sunday, fielding for the first half of the day before being called to the crease just six overs into England's innings.

Temperatures at nearby weather bureau stations reached 43.4 and 43.7 degrees, above the record 43.1 taken during the 1908 Adelaide Ashes Test.

A heat stress tracker, taking into account environmental factors for a 'feels like' mark, at the ground also displayed a reading of 57.6 in the middle.

England blamed a gastro bug rather than Sunday's temperatures, but it still prompted debate on whether the International Cricket Council needed to introduce a policy to protect players in extreme conditions.

Former Australian Test batsman Dean Jones, famous for his hospitalising double century in extreme heat during the 1986 tied Test in India, called for games to be suspended in extreme heat.

"After speaking to a couple of doctors this morning ... in my opinion cricket should be called off after 41C ... it's a workplace issue now ... Just my opinion," he tweeted on Monday morning.

It's understood Australian players felt the conditions much more in the oppressive heat during last year's tour of Bangladesh, where Peter Handscomb and Pat Cummins were particularly affected.

A common-sense approach is largely taken by match officials in elite Australian cricket matches during the heat.

Extra drinks breaks were added on Sunday, while medical officials kept a closer eye on players. Messages over the big screen also prompted fans to be sun-safe and hydrate.

A round of Sydney grade cricket - governed by the state body - was called off last summer in severe heat, however a Sheffield Shield match continued in the city in the same conditions.

But players in Shield and other elite matches have access to ice jackets, misting fans and scientific analysis that amateurs do not.

Root's incredible display of courage on Monday was reminiscent of South African skipper Graeme Smith's efforts at the same ground in 2009.

Smith came out to bat late on the final day of the third Test, despite suffering a broken hand from a Mitchell Johnson thunderbolt.

Smith was eventually dismissed just 10 balls short of saving the Test for his side.

with AAP