Fans stood under cooling mist fans at Melbourne Park to beat the heatDates: 16-29 January Venue: Melbourne ParkCoverage: Commentary every day from 07:00 GMT on Radio 5 Sports Extra 'Tennis Breakfast' live from Melbourne, with selected live text commentaries and match reports on the BBC Sport website and app.The majority of play was suspended on day two of the Australian Open because of extreme heat in Melbourne.
With temperatures above 35C, matches on the outside courts were stopped just before 14:15 local time (03:15 GMT).
Britain's Dan Evans was involved in one of them, leading two sets to one against Argentina's Facunado Bagnis.
Andy Murray's match against Matteo Berrettini was allowed to start at about the same time because it was under the roof on Rod Laver Arena.
Matches on Margaret Court Arena and John Cain Arena - which both also have a roof - were allowed to continue.
Play stopped outside when the Australian Open heat stress scale - which takes into account the strength of the sun, air temperature in the shade, relative humidity, and wind speed - reached its highest level of five.
It will resume at 17:00 local time (06:00 GMT), with organisers saying the tournament referee would continue to review conditions.
The extreme heat policy had earlier come into effect when the scale hit four, allowing singles players to take a 10-minute break during the match and have a shower or use cooling rooms.
Evans, like many of the players who were involved in the earlier matches, used an ice pack on his head during changeovers.
Estonian 16th seed Anett Kontaveit had only played two games against Austria's Julia Grabner when the pair had to leave the court
