Stage four on Saturday will see the riders take on a 24km time trial and Backstedt, winner of five time trials so far in her short career, will be among the favourites to take back-to-back victories.
“Tomorrow will be super brutal with the heat,” she said.
“Every day has been super hard with the heat, and the climbing, but tomorrow it should be a good day for me again.”
The five-stage Tour de Suisse Femmes concludes with a mountain loop starting and finishing in Villars-sur-Ollon on Sunday.
In the men’s race, Ecuador rider Jhonatan Narvaez took a sprint finish to win stage three from Xandro Meurisse of Belgium.
Tadej Pogacar, whose fiancee Urska Zigart broke her jaw in a heavy crash on Thursday, retained the yellow jersey.
The UAE Team Emirates-XRG rider sat in the peloton after two days of attacking, and holds a lead of two minutes and 50 seconds over Richard Carapaz.
There are two stages left with the race finishing in Villars-sur-Ollon on Sunday.