It is a favourite joke of Billy Connolly that when the Scots first came across Perth in Western Australia, with its natural beauty but intense heat, they must have hurried on through, heading for New Zealand's south island and the comfort of occasional wind and sideways rain.

Had Andy Murray been on that ship with the first group of Scottish settlers in 1829, he might have jumped off, rolled up his sleeves and started running around.

It has always been one of the mysteries of the tennis tour that having been raised in Dunblane, where cool, windy and wet days are the norm, Murray should somehow be most at home when the temperatures go up.

Of course, no one is at their best on a tennis court when the temperatures are in the 40s, as they were when Murray practised before his opening match at the Hopman Cup on Monday.

But the Scot has always adhered to the idea of the survival of the fittest, that the harder you work, the more success will follow.

It's an ethos that has served him well and as he walloped Benoit Paire in his opening match of the mixed team event here on Monday, it was plain to see that the work he put in with Amelie Mauresmo and his team in Florida in the short off-season is already paying off.

Murray looks supremely fit, which is probably why a niggling pain in his left shoulder should be so annoying for him.

The Scot showed no signs of discomfort during the match with Paire, barring the moment towards the end when he ripped off the protective tape that had become itchy with sweat.

But the pain, he said, is more noticeable when he serves, or even when doing non-tennis related things like opening doors, or signing autographs.

Considering the scan he had on the shoulder before leaving Abu Dhabi was all clear, no real damage would appear to have been done and it wouldn't be a Murray week if there was not some sort of niggle to concern him.

Having teamed up with Heather Watson to win the deciding mixed doubles - and the match - against France, Britain were due to take on Poland in the early hours of this morning, a match which pitted Murray against the giant figure of Jerzy Janowicz.

Temperatures in Perth were expected to be in the mid-90s against today, tough but nothing compared to the 44 degrees Murray practised in on Monday.

The retractable roof on the Perth Arena comes in very handy when the weather gets out of hand and a victory over the Poles would keep Britain on track for the final.

Murray will stop at the first sign of significant pain, no doubt, but momentum is a great thing at the start of the new year, and having won the exhibition event in Abu Dhabi, it's so far, so good.

Serena Williams, meanwhile, was barely at the races yesterday as she was hammered by Eugenie Bouchard as the USA lost to Canada.

Having asked for a coffee when trailing 5-0 in her opening match, before recovering to win, the world No.1 was at a loss to explain.

"I don't know what's wrong with me, I am so tired, it's so weird," she said. "I can't get my body to move and I feel like I have no energy. It is a little frustrating because I know I can play 2000 times better."