I was distracted by Jamie's pain, reveals Andy Murray

This was another day of biblical extremes at the Australian Open: first searing temperatures, and then thunder, lightning and intense humidity. It was all too much for Jamie Murray, Andy's older brother, who developed such serious heat exhaustion that he was laid low by multiple cramps.

Andy Murray also looked a little out of sorts as he played a peculiar match against Vincent Millot, the squat French left-hander who - at No267 in the world - was the lowest-ranked player left in the men's draw. But then, as Murray explained, he found it tricky to focus while his brother was racked with pain. "What was happening with Jamie was more important than my match," said Murray after his up-and-down 6-2, 6-2, 7-5 win.

"It was a little distracting as well and you just try not use up any extra energy." After beating Go Soeda on Tuesday, Murray had already questioned whether the authorities at Melbourne Park are too cavalier with the players' health and safety. But this was different. It was his own flesh and blood. "It is easy to say Jamie was only playing doubles and it's not as physically demanding as the singles," Andy explained.

"It wasn't so much that he was cramping but that he was scared. He's never dealt with anything like that before and being on your own, it's difficult, so I tried to make sure someone was around him the whole day." At least both Murray brothers won their matches. Jamie was playing with his regular partner, John Peers, a Melburnian by birth, against two more Australians: Matt Reid and Luke Saville. They scored a 7-6, 7-6 victory in 1hr 50min, and it was not until later that Jamie's exertions began to catch up with him.

"He was a bit tired and sore when he came off the court," said Murray, "but then it hit him like an hour and a half later. I've never had it like that. "He was struggling for a good three, four hours after the match. He's never had real cramps like that either. I don't know how dangerous they are, but they're very, very uncomfortable. One part of your body goes, and then, when you move, the opposite muscle goes. When it happens the first time, it's pretty scary. Hopefully he'll be fine tomorrow."

Murray and Peers had started their match in the Rod Laver Arena soon after 11am, when the temperature stood in the high nineties. A couple of hours later, the mercury climbed above 110F (43C) for the first time in this extraordinary week, prompting tournament referee Wayne McEwan to invoke the "extreme heat rule" and suspend play for around four hours. Later, a deluge of gobstopper-sized raindrops flooded the courts and knocked the singles players even further behind schedule.

Andy Murray was far from being the last man off court when he finally subdued Millot at 11.58pm. Having been 5-1 down in the third set, he saved a set point in the next game, and then sprinted for the line with an unbroken sequence of 23 straight points. Although Murray once won 14 straight points against Feliciano Lopez - the Spaniard who also happens to be his next opponent here - he reckoned that this was comfortably the longest streak of his career.

Millot, who had won only one grand slam match in his career, made an unpredictable opponent. One regulation forehand bounced before it reached the net. But then, at the start of the third set, he suddenly started playing like the eponymous Laver - another powerfully built 5ft 8in leftie.

For 20 minutes, there were aces and return winners and some scorching drives down the line off both wings. Then Murray broke back to move to 2-5, and the magic dried up as abruptly as it had arrived. So now for tomorrow's third-round match against Lopez, a man Murray holds a 7-0 head-to-head record against. Although perhaps this Lopez will be different, given that he shaved off his trademark Pre-Raphaelite locks on New Year's Day.

"I was in the ice bath with him after our first-round match and talking to him about it," said Murray. "His hair was something that made him Feliciano. He's a bit different now." One woman who may be disappointed is Murray's mother Judy, who once gave Lopez the self-explanatory nickname "Deliciano". "What can I say?" Lopez smiled yesterday. "Judy is so fine."