Abstract: A handheld appliance having a body and an attachment, the body including an outer tube and fluid flow path extending from a fluid inlet to a fluid outlet within the outer tube and a printed circuit board (PCB) arranged within the fluid flow path wherein, the PCB is housed within a housing. The body may further include an inner wall and the inner wall provides the housing for the PCB and the fluid flow path may extend around the housing. The housing may be generally rectangular and may extend across an internal radius of the outer tube. The fluid flow path may extend around both sides of the housing. The housing may include a heat sink which may be in contact with the fluid flow path on one side and with components on the PCB on the other side.