@Carol302
There are some things you can do.
Firstly, I'd suggest getting the facts at :-
https://www.who.int/emergencies/diseases/novel-coronavirus-2019
https://www.cdc.gov/coronavirus/index.html
There have been a small number of reports that people with novel coronavirus (2019-nCoV) have transmitted it while showing no symptoms. This has, to date, not been confirmed by any reputable scientific source that I have seen.
The most up-to-date information suggests human-to-human transmission after symptoms start to show, between persons in close contact, and after an incubation period of about 14 days. Of course, this could change as more information is known.
The best thing you can do is learn the facts about protecting yourself, and implement a proper cleaning protocol between guests, based on your particular situation.
There is an abundance of this information on the websites I already posted.
Of course, one should be doing all this during cold and 'flu season anyway, to protect oneself and one's guests from sharing viruses and getting sick.
An elevated temperature is not going to tell you what kind of illness a person may have.
Symptoms of novel coronavirus (2019-nCoV) include cough, shortness of breath and fever. It can only be diagnosed by trained medical personnel applying the appropriate screening test.
If someone displays the symptoms above, they should immediately seek medical attention, and be prepared to disclose their travel history.
Hope this helps.