An A&E nurse is being treated in intensive care after contracting coronavirus.
The man, in his 60s, has been intubated and is on a ventilator at Southend Hospital, according to sources at the facility.
It comes after staff at the site warned bosses they feared for their safety due to a lack of protective equipment.
Hospital management said they were "absolutely committed" to staff safety and would go beyond official advice.
Southend Hospital chief executive Clare Panniker told staff on Wednesday, that protective gear - such as gloves, aprons and surgical masks - could be used throughout the hospital but respiratory masks should only be used where virus patients were on oxygen.
In a letter to management on Wednesday, medics said they were not receiving the correct personal protective equipment (PPE) and that most had not been tested for the virus.
Ms Panniker has replied to staff saying: "We have today made the decision to go above and beyond the PHE guidance and advise all staff coming in contact with patients in clinical areas to wear gloves, aprons, and surgical masks.
"We are in the process of making this available to all areas that need it."
One medic described this as "good news" but said there was nothing in the letter to address concerns about supply and access to PPE.
Staff have warned they could limit services due to fears for their safety but one medic told the BBC "we wouldn't do anything to jeopardise the care and treatment of our patients".
The hospital press office refused to confirm whether a nurse was in intensive care, saying it was "unable to comment on individual patients".