Today’s correspondent asks:
What is the obligation for various state ES to issue emergency fire shelters to their volunteers including SES (issued polyester uniforms) sent to support fire operations?
Given polyester uniforms; how many SES volunteers when deployed to support fire service operations; are also lent temporary fire shelters?
That link is to a page hosted by the Wildfire Today where they have “13 videos about fire shelter deployments on wildland fires”. The introductory page says:
Fire shelters are small foldable pup tent-like fire resistant devices that a wildland firefighter can unfold and climb into if there is no option for escaping from an approaching inferno. Many firefighters have used the devices successfully, but others have been killed inside them.
As has been said so often, answers to questions like this are not answered by law; they are a question of risk assessment. An emergency service has to consider what is the risk to its members and how to address that risk (Model Work Health and Safety Act 2011 ss 18 and 19). Providing a fire shelter is a last resort and many services would seek to have other responses to the risk of getting caught in a fire particular where the service is an SES and not a fire service (see SafeWork Australia Model Code of Practice: How to manage work health and safety risks (May 2018) [4.1] ‘The hierarchy of control measures’). Further fire shelters are not particularly safe, some people have survived in them, others have died.
So the obligation (if there is one) is to provide a fire shelter if a risk assessment says that is the best response to a risk that staff and volunteers might face.
Australian Emergency Law 
Have never heard of them being used in Australia
These things are not called “shake & bake” tents for no reason! Used one in a hazard reduction burn on Black Mountain ACT in 1967. Low intensity fire but the tent caught fire and the occupant suffered burns. Use other strategies if you want to stay safe.
Polyester uniforms are a PR uniform. If you are being deployed into a fire zone you would be expected to wear your “heavy weight uniforms, either overalls or two piece. Common sense would tell you not to wear polyester uniforms for these tasks. Any “crew leader, staging manager or OIC should not allow you into these areas, even for support roles within the fire zones.