Fire-fighters were still at the scene of a North Lakes blaze late Saturday morning after they received a call at 10.05am to a College Street property.

Police said one of the unit's occupants, a 36-year-old man, was taken to Redcliffe Hospital with minor burns to one of his hands.

"Investigations into the cause of the fire are continuing, but the incident is being treated as suspicious," police said in a statement.

A Queensland Fire and Emergency Services spokeswoman said the house was "well involved" when fire-fighters arrived.

The fire was brought under control and the fire investigation unit was on the scene, she said.

The blaze came after three pre-dawn fires on Stradbroke Island, at Toowoomba and in central Queensland.

The Straddie Styles Hair Salon in Dunwich, on North Stradbroke Island, went up in flames at 12.30am.

There were no occupants in the one-storey brick building, with the fire extinguished at 1.29am.

Twelve minutes later at 1.41am, in Toowoomba, a fire was reported on the ground floor of a two-level timber Hume Street house.

The fire was reported extinguished at 5.29am, the QFES spokeswoman said, with crews still on site "mopping up".

And finally, fire crews attended a Mount Morgan blaze at 2.44am.

The QFES spokeswoman said the upper level of the two-storey building on James Street was "well alight" when fire-fighters arrived.

All occupants at all Saturday's fire sites were accounted for, she said.

Meanwhile, QFES crews were conducting planned hazard reduction burn west of Townsville on Saturday morning.

The burn had resulted in heavy smoke around Darling Road, Jensen, which led to warnings for motorists to use caution on the roads.

Nearby residents were advised to keep windows and doors closed.