1-866-553-7205 The Telephone Health Advisory Service (THAS) is an after-hours telephone health advice and triage service for enrolled/registered patients of a Family Health Team (FHT) in Ontario. Patients who call THAS have access to Ontario Registered Nurses who will provide them with symptom based health advice and information. In addition, for enrolled/registered patients, THAS nurses have access to the FHTs’ on-call physicians and when appropriate will call the physician for secondary triage regarding the callers’ concerns.