A stand mixer (10) capable of subjecting ingredients in a bowl (60) to a planetary mixing action, and which is also provided with the capability of heating the ingredients, is further provided with a guarding device (70, 80) to reduce unwanted egress of steam and/or to prevent ingredients being ejected from the bowl (60). The guarding device comprises a first component (70) which is removably attachable to the stand mixer (10) in the vicinity of its planetary drive outlet (44) and a second component (80) which is removably attachable to the first component (70) and also to the bowl (60). The first component (70) is shaped and configured to shield part of the stand mixer (10) from heat and the second component (80) is designed to resist unwanted egress of steam and/or to prevent ingredients being ejected from the bowl. A user is thus provided with the flexibility of operating the stand mixer with just the first component (70) in place as a heat shield, thereby leaving the bowl (60) open so that steam can escape, or operating the stand mixer (10) with both components (70, 80) in place, in which case the bowl (60) is effectively covered.