The Grove Racing driver is known to have suffered with cabin temperatures during the previous campaign, despite Supercars drivers generally using cool suits during longer races.
He was worst affected in the opening leg of the Gold Coast 500 while trialling an electric cool suit as opposed to the traditional dry ice system.
Reynolds managed to survive a gruelling 250-kilometres around the brutal street circuit and finish second, but needed to be monitored by medical staff during the post-race media conference.
While the lower-downforce Gen3 cars aren't expected to create as much front-end heat that can soak through to the cabin, Reynolds isn't taking any chances ahead of the new season.
Speaking as part of an Australian Grand Prix announcement today, he revealed that he has purchased a home sauna to better prepare his body for long, hot races.
“Last year, I struggled with the heat really bad,” said the 2017 Bathurst 1000 winner.
“For some reason, our car was a lot hotter than all the other cars, so how I’ve prepared myself this year is I’ve bought a little sauna – a box with a door that can get really hot – that I can sit in there to try and get used to the heat again.
"So that’s one thing I’ve done different."
Reynolds added that his pre-season preparation has also included trying to rid himself of old habits that only worked in the previous-generation of car.
"Given the cars are so new to drive, I'm trying to forget all the old techniques that I used to have driving the old cars," he said.
"I'm still learning, it's still very new for all of is. Hopefully I can understand it quicker than everyone else. But I really don't know."
The new season, and new era for Supercars with the Gen3 cars, will kick off on the streets of Newcastle in just eight days time.
As it stands there are still a number of question marks over the final specification of the cars, with concerns over parity still being addressed with ongoing aero testing.
Reynolds has been one of the more outspoken drivers on the matter, last week refuting claims of sandbagging during testing by the Chevrolet teams and expressing concern over a perceived pace deficit for the Mustang.
