Two deliberately lit fires were brought under control by evening on Thursday, and TFS Regional Chief North Ian Bounds is appealing for information on the arsonists.
"It's certainly behaviour we don't need at this time, especially when we have high fire risk days [like Thursday]," he said.
"The potential to injure someone through these actions is criminal. If anyone has any credible evidence or information about these fires, we urge them to report through Crimestoppers."
The deliberately-lit blazes burned 1300 hectares at Mathinna, and two at Mangana.
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Mr Bounds praised the hard work of about 60 TFS and Sustainable Timber Tasmania personnel at Mathinna, and about 20 at Mangana, in containing the blazes and protecting property.
Firefighters on the ground were supported by four helicopters across both blazes.
But Mr Bounds said firefighters do not have an easy season ahead of them - a season which is likely to extend until April, unless there is significant statewide rain.
"Over the next few days we will see conditions settle, and that's a pattern we expect to see continuing possibly up until Christmas: cool days, followed by periods of high fire danger. We expect to see that trend happening weekly or fortnightly.
"The problem is the serious deficiency in rainfall over autumn, winter, and now into spring."
Conditions on Thursday brought winds of up to 70 km/hr, Mr Bounds said, and temperatures reaching up to 38.3 degrees Celsius.
But the shock and awe-style strategy developed by the TFS over the past several years - of throwing resources immediately at new fires regardless of initial severity - proved effective on Thursday, Mr Bounds said.
He said the possibility there would not be interstate support this season was something the TFS was monitoring. So far this spring six lives, 612 homes and millions of hectares have been lost to bushfires on the mainland.
There are 23 Tasmanian volunteer firefighters in Queensland.