The Melbourne heat took out Vodafone mobile service for more than three hours last night, according to the number three telco.
Melbourne temperatures hit nearly 39 degrees Celsius on Thursday, according to Weather.com.
"We experienced a disruption to services at approximately 7:45 pm last night caused by a failed air-conditioner and over-heating of infrastructure in extreme weather conditions," a Vodafone spokeswoman said. "We apologise for the disruption and services were restored at approximately 11:15 pm."
"We believe this to be a one-off but will review our processes to reduce the impact in the unlikely event this should happen again."
Vodafone has previously acknowledged that network issues have plagued its business and is currently making large investments in its network.
Earlier this year, Vodafone suffered a massive outage that took out data services in six states.
However, the Telstra and Optus networks have not been immune to outage this year, either. Optus and its resellers suffered a three-hour 3G outage in July due to a router issue. Telstra mobile customers dealt with call failures in late July.
Sign up for CIO Asia eNewsletters.