Kaikohe fire chief Bill Hutchinson said if an investigation found the fire had been started by a spark from a bee smoker, as suspected, it was an indication of just how dry and volatile vegetation was in the Mid North.
The beekeeper was taken to hospital as a precaution suffering from smoke inhalation and possible heat exhaustion.
''Quite a lot of beehives were lost, which is tragic.''
Hutchinson said ''millions'' of bees were flying around but only one firefighter was stung.
Bee smokers are used to produce puffs of smoke which subdue bees when their hives are being handled.
Northland deputy principal rural fire officer Clinton Lyall confirmed beekeeping activities were the likely cause of the fire.
Contractors and a Kaikohe rural fire crew returned to the site yesterday to continue dampening down.
Lyall urged businesses using hot-work practices outdoors to be cautious, especially in the heat of the day between 2 and 5pm, and to consider whether they were absolutely necessary given the current extreme weather conditions.
The beekeeper is believed to be the first person in Northland taken to hospital as a result of a fire so far this summer.
In 2013 a man was critically injured when a burn-off got out of control at Waimahana Bay, east of Mangonui, and in 2011 a helicopter pilot and a Department of Conservation ranger died going to aid of people trapped by a deliberately lit fire on the Karikari Peninsula.
Despite an extensive investigation no one has been charged in relation to the Karikari fire.