Do Thermacell spatial repellers actually work?

Across the reviewers we read, the consensus is that Thermacell heat-activated repellers create a genuinely effective bubble of protection in still air. High-trust threads on r/CampingGear and r/camping repeatedly describe a near bug-free zone within about 15 minutes of starting one up. The major, near-universal caveat is wind: in open or gusty conditions the protective zone is blown away and effectiveness drops sharply.