An apparatus to deliver humidified gas to a patient during a medical procedure, the apparatus being configured to deliver humidified gas during an open medical procedure, or during a closed medical procedure, the apparatus comprising: a humidifier including: a humidification liquid chamber; a heater to heat humidification liquid in the humidification liquid chamber to generate vapor to humidify the humidified gas delivered to the patient; and a hardware controller configured to select a mode of operation from a first mode associated with the open medical procedure and a second mode associated with the closed medical procedure; wherein the hardware controller is configured to select the mode of operation by monitoring an electrical characteristic of the heater and select the mode of operation in response to the monitored electrical characteristic, wherein the monitored electrical characteristic is power drawn by the heater, a power duty cycle of the heater or current drawn by the heater; wherein the hardware controller is configured to execute an initial heater warm-up process wherein power is provided to the heater until it reaches a predetermined threshold temperature; wherein the hardware controller is further configured to implement a heater control with respect to the initial heater warm-up process; wherein a set point temperature of the heater is adjusted based on an initial set point temperature of the heater, the heater temperature being controlled such that the level of humidity of the humidified gas delivered during the warm-up process is controlled; wherein the hardware controller is further configured to implement a heater plate temperature control with respect to the initial heater warm-up process according to the following equation which is used to adjust the set point temperature of the heater plate based on the initial set point temperature: Set point temperature = gradient * time + initial set point temperature. a humidifier including: a humidification liquid chamber; a heater to heat humidification liquid in the humidification liquid chamber to generate vapor to humidify the humidified gas delivered to the patient; and a hardware controller configured to select a mode of operation from a first mode associated with the open medical procedure and a second mode associated with the closed medical procedure; wherein the hardware controller is configured to select the mode of operation by monitoring an electrical characteristic of the heater and select a humidification liquid chamber; a heater to heat humidification liquid in the humidification liquid chamber to generate vapor to humidify the humidified gas delivered to the patient; and a hardware controller configured to select a mode of operation from a first mode associated with the open medical procedure and a second mode associated with the closed medical procedure; wherein the hardware controller is configured to select the mode of operation by monitoring an electrical characteristic of the heater and select the mode of operation in response to the monitored electrical characteristic, wherein the monitored electrical characteristic is power drawn by the heater, a power duty cycle of the heater or current drawn by the heater; wherein the hardware controller is configured to execute an initial heater warm-up process wherein power is provided to the heater until it reaches a predetermined threshold temperature; wherein the hardware controller is further configured to implement a heater control with respect to the initial heater warm-up process; wherein a set point temperature of the heater is adjusted based on an initial set point temperature of the heater, the heater temperature being controlled such that the level of humidity of the humidified gas delivered during the warm-up process is controlled; wherein the hardware controller is configured to execute an initial heater warm-up process wherein power is provided to the heater until it reaches a predetermined threshold temperature; wherein the hardware controller is further configured to implement a heater control with respect to the initial heater warm-up process; wherein a set point temperature of the heater is adjusted based on an initial set point temperature of the heater, the heater temperature being controlled such that the level of humidity of the humidified gas delivered during the warm-up process is controlled; wherein the hardware controller is further configured to implement a heater plate temperature control with respect to the initial heater warm-up process according to the following equation which is used to adjust the set point temperature of the heater plate based on the initial set point temperature: Set point temperature = gradient * time + initial set point temperature.