Aaron Burns' strike secured Linfield a famous 1-0 Europa League win against Xanthi in Greece.
Blues manager David Jeffrey had admitted concerns over the heat's impact on his players in the build-up to the second qualifying round first leg.
However, the Northern Irish side faced similar energy-sapping conditions against AEL Limassol in last season's Champions League and had clearly learned from that experience.
Burns grabbed the winner in just the 25th minute, firing past Christian Gimenez after good work down the left.
Xanthi enjoyed the lion's share of possession after the goal, but Linfield held on to take a 1-0 lead into next week's second leg at Windsor Park.