An apparatus for applying negative pressure to a wound, the apparatus comprising: a negative pressure source configured to provide negative pressure to a wound dressing via a fluid flow path; a switch comprising an actuator configured to toggle a state of a first pair of electrical contacts and a state of a second pair of electrical contacts in response to a user input, the switch being configured to receive the user input as a depression of the switch; and control circuitry configured to: supply negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically connected state and the second pair of electrical contacts being in the electrically connected state, disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically disconnected state or the second pair of electrical contacts being in the electrically disconnected state, and wherein the control circuitry is configured to disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in the electrically connected state and the second pair of electrical contacts being in the electrically disconnected state. a negative pressure source configured to provide negative pressure to a wound dressing via a fluid flow path; a switch comprising an actuator configured to toggle a state of a first pair of electrical contacts and a state of a second pair of electrical contacts in response to a user input, the switch being configured to receive the user input as a depression of the switch; and control circuitry configured to: supply negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically connected state and the second pair of electrical contacts being in the electrically connected state, disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically disconnected state or the second pair of electrical contacts being in the electrically disconnected state, and wherein the control circuitry is configured to disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in the electrically connected state and the second pair of electrical contacts being in the electrically disconnected state. supply negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically connected state and the second pair of electrical contacts being in the electrically connected state, disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in an electrically disconnected state or the second pair of electrical contacts being in the electrically disconnected state, and wherein the control circuitry is configured to disable supply of negative pressure with the negative pressure source in response to the first pair of electrical contacts being in the electrically connected state and the second pair of electrical contacts being in the electrically disconnected state.