ST KILDA coach Scott Watters has called for the AFL to review its heat policy after his players were forced to battle it out in 38-degree conditions and stifling humidity at AAMI Stadium in Sunday's NAB Cup games.

Despite the torturous conditions, the AFL refused to reduce the length of the 20-minute halves to 17 minutes.

The Saints opened the afternoon's play taking on Adelaide, then had to back up immediately taking on Port Adelaide in game two.

Watters admitted his players were left exhausted by the end of the second game, sentiment backed up by their 50-point loss to the Power in game two after they accounted for the Crows by 26 points in game one.

"We have to have a close look at the heat policy, I mean that was pretty hot," Watters said.

"The only adjustment was two extra water carriers today, those players were under a fair bit of pressure in the second half.

"We tried our best to rotate them, but at the end of the day when you're playing in that sort of heat it's testing, particularly for younger players.

"They are fit, our players, but that was pretty tough."

AFL media relations manager Patrick Keane said the league would take Watters' suggestion for a review into account.

"The two quarters we play are obviously shorter than a normal quarter, the benches are significantly bigger than for a normal AFL game and once you've played the first game you can swap up to seven players for the second game," Keane said.

"We'll assess that and make a judgment call."

Watters said club doctors were well aware of the dangers playing in such heat posed to the players and would need to monitor players closely for signs of heat stress-related illness.

"Our medical staff, coming into a game like today, are already on high alert, but that's a test of our professionalism to recover," he said.

"Our younger players in particular, this is what being an AFL footballer is all about; except the conditions, be professional, get back up as soon as possible."

Shortened halves could have been considered, Watters said, but the option to include more players in his game-day squad would have been preferred.

The St Kilda coach was concerned capped rotations in the remaining NAB Cup games could lead to injury, particularly when he was bringing players back into the side.

"I don't know about the halves, maybe a few extra players? Maybe shorter halves, but at the same time we're trying to get some mileage into our players knowing that we have limited rotations coming up in NAB Cup weeks two, three and four," he said.

"I'm not a fan of capped rotations, particularly when you're trying to prepare players and coaches need that flexibility to bring players back from injury and we'd like to be able to modify their preparation or their time playing in games.

"Next week and in weeks three and four you've got to be really, really cautious exposing your player to a game where there is only 80 rotations…our medical staff will have a lot of work to do over the next couple of weeks."

Crows coach Brenton Sanderson said the club had been contacted by the AFL early on Sunday and were told the league felt no obligation to shorten the matches regardless of the heat.

"The AFL rang us today and said because the halves have been going for 20 minutes, there haven't been many stoppages and with six on the bench they felt no need to change it," Sanderson said.

Having played St Kilda in game one, then the Power in game three, Sanderson said his team was aided by the break in between games as it allowed the side to "cool off" in its change rooms.

"With the conditions today, I think it was 38 [degrees] for most of the three games, we've got the advantage here with our change rooms, we've got the cold baths and the pool and stuff so our players could at least cool off [during the break]," he said.

"It probably did help us a bit coming out for game three."

Harry Thring is a reporter for AFL Media. Follow him on Twitter: @AFL_Harry.