Most international students are not entitled to publicly funded health services with New Zealand. If you receive medical treatment during your visit, you may be liable for the full cost of treatment. Full details on entitlements to publicly funded health services are available through the Ministry of Health and can be viewed here.
The Accident Compensation Corporation provide accident insurance for all New Zealand citizens, residents and temporary visitors to New Zealand, but you may still be liable for all other medical and related costs. Further information can be viewed here.