Calls for New Zealand to be better prepared for a thunderstorm asthma outbreak

Thunderstorm asthma is where asthma cases needing hospital care double, because of a thunderstorm.

It's caused by a thunderstorm in the summer that breaks pollen particles into pieces so small, they start to block peoples lungs -- even those who've never had asthma before.

Massey University's Carol Stewart says New Zealanders need to know about what to do -- now.

She says we need to develop health messages now, so health services aren't scrambling when a thunderstorm outbreak happens.