A Guelph woman’s attempt to become the first deaf swimmer to cross Lake Ontario ended abruptly due to a medical emergency.

Brenda Lussier had set off from Port Dalhousie Sunday afternoon, bound for Toronto.

Dubbed the Silent Swim, Lussier’s trek was organized as a fundraiser for cystic fibrosis.

Her body temperature started to increase not long after she began her journey. By late Sunday night, she was feeling disoriented and told her crew that she nearly lost consciousness at one point.

She was pulled from the water, having completed slightly less than half of the swim, and taken for medical examination.

It is believed she was suffering from dehydration and exhaustion, as well as disorientation.

The Silent Swim had been Lussier’s third attempt to cross the lake. Earlier bids were called off due to dangerous conditions on the water and a separate medical issue.