On 31 January 1941, Dreschel arrived at Ravensbrück concentration camp to receive guard training.
She initially held the position Aufseherin at Ravensbrück, the basic role of a female guard, and was in charge of interned women.
On 27 April 1942, Dreschel was selected for transfer to the newly opened Auschwitz II – Birkenau concentration camp in occupied Poland.
Her appearance was reportedly repellent, as one female Auschwitz prisoner recounted: "camp leader Dreschel was there, her buck teeth sticking out, even when her mouth is closed."
[2] She carried out indoor selections wearing a white coat and white gloves, disguised as a doctor.Once Mrs Drechaler [Dreschler] came, with her huge bloodhound, undressed everybody, took away even our shoes, and we had to stand for hours completely naked, none of us were thinking of life any more, the gas chamber seemed unavoidable.Dreschel regularly moved between the Auschwitz I camp and Birkenau, and involved herself in selections of women and children to be either exploited as slave labor, or murdered in the gas chambers.