The work presented here is an implementation of PID control to achieve a required supply air temperature in PEM(Personal environment module). In PEM, the air is heated to the required temperature while it flows through the supply duct, without any mixing chamber. This makes the control of air temperature in PEM difficult. Linear dynamic model of heat transfer in PEM is first obtained. Then P, PD and PID type control systems, to provide the rapid response without overshoot and saturation, are designed and implemented experimentally. Data obtained shows that the control system satisfied the design criteria and works properly in controlling the supply air temperature.