Older people are being urged to stay hydrated as hot and humid weather continues across the motu.
On Monday, Wellington airport reached 29.5 degrees, its highest January temperature since records began.
Hato Hone St John has reported a 22 percent increase in the number of call-outs for temperature related incidents in the last year.
Medical Director of the Royal College of GPs Dr Luke Bradford spoke to Ingrid Hipkiss.
