Workers at Wellington Hospital describe symptoms of dizziness and burning lungs, after being exposed to fumes from a diesel heater

The heater was used in a temporary Covid-screening structure erected outside the hospital, during the Omicron wave.

Despite symptoms described by workers, a DHB assessment has found no meaningful levels of carbon monoxide.

Medical Officer of Health Denise Barnfather says they can be hard to detect - both in people and in environments - and depends when the test was conducted.

Nonetheless, Worksafe ordered the heater's removal, and warned them to better manage the risks of diesel exhaust emissions.

The DHB says it's considering the improvement notice, and what measures are available to it.