Mercedes fixed the car in time for George Russell to partner Hamilton in the second practice session, in which the 39-year-old impressed ahead of qualifying day.
However, if the timesheet made it seem like it was smooth sailing for the seven-time world champion, things got heated inside the car.
Red has always been the theme of the Italian Grand Prix, especially this year with the usual Tifosi colours to support their adored team Ferrari mixed in with red-hot weather.
Hamilton has already found an inventive way of beating the heat at the Temple of Speed, making some modifications to his long-sleeved Mercedes t-shirt by cutting some of the excess material off.
Whilst in the cockpit for practice, he reported an additional issue with the temperatures, possibly owing to a fault with his W15.
“The seat is getting very hot,” he mentioned over team radio during FP1.
After the session, he explained to Sky Sports just how uncomfortable the feeling was: “It was ridiculously roasting in our car, for [what reason] I'm not quite sure exactly, [but] I think down by the radiators there's probably some leakage of hot air.
“So, yeah, it was very hot,” he added. “Like sitting on a sauna with no shorts on sort of pain!”