The Australian Open sick bay is overloaded, with player withdrawals now reaching record numbers at sweltering Melbourne Park.

Croatian Ivan Dodig is the latest casualty, the 32nd seed calling it quits on Wednesday while trailing Bosnian qualifier Damir Dzumhur 4-6 4-6 6-3 4-1 in their second-round encounter.

Dodig pulled the pin after cramping up in the scorching conditions at the season’s first grand slam event.

His mid-match withdrawal follows a record number of first-round singles retirements due to the Melbourne heatwave.

All up, eight men and one woman were unable to complete their opening matches, equalling the record for most retirements in a single round at any major in the 45-year professional era.

There were also nine retirements in the first round at the 2011 US Open in New York and nine in the second round at Wimbledon last year.

Dodig joins Australian Bernard Tomic, Germans Tommy Haas and Julian Reister, Kazakhstan’s Andrey Golubev, Americans Alex Bogomolov Jr and John Isner, Czech Radek Stepanek, Dutchman Robin Haase and Slovenian Polona Hercog in the casualty award.