Consider following two statements

A) If heat is added to a system, its temperature must increase

B) If positive work is done by the system in a thermodynamic process its volume must increase
 

It is not necessary that temperature must increase if heat is added because in isothermal process, change of state takes place at constant temperature.

Work done by system is given as $W=\int pdV$

and therefore if positive work is done, volume should increase.