Jamie Murray had a sudden heartstroke after last match

Great Britain Davis Cup captain Leon Smith revealed Murray needed extensive treatment after suffering from the effects of the heat.

The Scot, also the Lawn Tennis Association's head of men's tennis, told BBC Radio 5 Live: "About 15-20 minutes after the match finished he started to feel unwell and a bit of cramp and that is what the heat has done for him.

"But there is a great team in the locker room and they have kept him moving around for a couple of hours and getting the salts back in his body.

"He will be okay but he's got to work hard for the next couple of hours. He'll feel like sitting down but he needs to keep active and getting the right things in his body.

Jamie Murray and Australian partner John Peers battled their way into the second round of the men's doubles at the Australian Open with victory over Matt Reid and Luke Saville.

After wins on Wednesday for Colin Fleming and Ross Hutchins and Londoner Dominic Inglot and his Filipino partner Treat Huey, Murray and Peers triumphed 7-6 (7/4) 7-6 (8/6).

In the second round they will play Murray's former partner, American Eric Butorac, and South African Raven Kaasen, who put paid to the comeback of Pat Rafter alongside Lleyton Hewitt in round one.