SA fire trucks to help in Tasmania

South Australia's Country Fire Service has sent 10 fire trucks and four command vehicles to Tasmania to help with the fight against major bushfires.

The Tasmania Fire Service issued an emergency evacuation alert on Wednesday for the centres of Temma, Arthur River and Nelson Bay and has battled about 50 fires over the past two weeks.

The CFS says its fire units will arrive in Hobart on Friday and are being deployed ahead of any requirement for SA strike teams to also join the fight.

Chief officer Greg Nettleton says South Australia is always grateful for support from interstate and is happy to return the favour.

"Some of the fire behaviour has not been experienced before and there is potential for them to spread and impact on world heritage wilderness areas and populated areas," Mr Nettleton said.