A child and a baby suffered injuries in a head-on motor vehicle accident just north of Waiuku.

The Waikato Westpac Rescue Helicopter was dispatched at around 4.30pm on Tuesday to the incident.

A four-year-old boy and a nine-week-old girl suffered moderate injuries and were flown to Starship Hospital for treatment.

The children's mother was also airlifted to Auckland Hospital for treatment, says a rescue helicopter spokesperson.

Later that evening, the rescue helicopter was tasked to transport an elderly woman suffering a serious medical event from Tauranga Hospital to Waikato Hospital for specialist treatment.

The rescue helicopter was then dispatched at approximately 11pm to Taupo Hospital for a woman suffering a medical emergency.

She was transported to Waikato Hospital for specialist treatment.