The chief coroner and fire service are warning people to take care in the heatwave striking many parts of New Zealand, after a woman died in Christchurch on Wednesday.

The woman, in her early 60s, died from hyperthermia after overheating in Wednesday's high temperatures. People living with multiple sclerosis can struggle to control their body's temperature in hot weather.

READ MORE: How to stay cool during the summer heat

Chief Coroner Deborah Marshall says people with multiple sclerosis, particularly, need to take care in the heat following the death of a woman in Christchurch on Wednesday.

"Following this death, I feel it is important to remind people of the dangers of overheating due to the high temperatures expected in the coming days and to take all necessary precautions," Marshall said.

On Wednesday Christchurch soared to 32C as a spell of hot weather began to hit Canterbury and northern Otago.

Yesterday temperatures fell slightly beneath 30C but are expected back up to the stifling levels on Tuesday and Wednesday next week.

It is expected that the mercury in some parts of New Zealand will hit 40C next week.

Multiple Sclerosis New Zealand's welcoming calls from the Chief Coroner.

MSNZ vice president Neil Woodhams says it's important to raise awareness on how vital it is to stay cool. 

"It's very appropriate that the Chief Coroner makes a statement and we're very grateful that she's included us."

Woodhams says it's vital to take every step possible to stay cool.

"[People can] limit caffeine that can dehydrate you, sucking ice cubes, there are various cooling vests that you can put in the refrigerator and hang around your neck."

- additional reporting NZN, NZ Herald