The flat oyster Ostrea angasi was once a dominant ecosystem engineer throughout southern Australia, forming extensive reefs that have since been reduced to 1% of their historical coverage. Restoration of O. angasi populations has been gaining traction over the last decade, exclusively in subtidal habitats. However, evidence suggests O. angasi can survive in the intertidal zone, pointing to more cost-effective restoration. To quantify the tolerance of O. angasi to thermal and desiccation stress, individuals from 3 age classes (1, 4, 7 months) were exposed to air at 3 temperatures (10, 25, 40°C). Logistic regression revealed that survival rates depended on an interaction between emersion duration, temperature and shell length, with survival increasing as shell length increased, but decreasing as temperature and emersion duration increased. Our results suggest that O. angasi, like other Ostrea species, have some tolerance of thermal and desiccation stress. As field validation is needed to understand the effect of repeated tidal exposures and other factors affecting survival in the intertidal, we also present some preliminary field trial findings. Our results can inform restoration and aquaculture practices. Such exploration of unconventional restoration practices and a rethinking of habitat associations can improve the efficiency and cost-effectiveness of restoration efforts.