If you need emergency medical assistance while travelling in New Zealand, it is worth bearing in mind that they have a reciprocal health agreement with the UK. This means that certain services will be available to you at the same cost as it would be for an NZ national, or for free. The Health New Zealand website states that despite these services being available to you, “travellers should hold comprehensive travel insurance, including health insurance".
To check eligibility and read up on the specific healthcare available to you, we suggest that you familiarise yourself with Reciprocal Health Agreements – Te Whatu Ora - Health New Zealand.