There's a positive case of Covid in my household and I have an engineer visit booked. What should I do?

Our engineer will call on the day of the visit to confirm their estimated time of arrival.  They will also ask if anyone in the household has tested positive for Covid, and if so, they may ask that the person stays in another part of the home well away from where the engineer is working, goes out while the engineer is working (if asymptomatic) or that the appointment is rebooked.