The U.S. may be free of Ebola cases, but the upstairs neighbor isn't taking any chances. Canada is tightening precautionary measures on travelers coming from Sierra Leone, Liberia, and Guinea. Travelers deemed high risk, who have had direct contact with Ebola patients, will have to self-isolate at home or in a special facility for the three-week incubation period. Those without personal contact will be asked to self-monitor and take twice-daily temperature checks. Local health authorities can decide whether a returning health-care worker will have to be quarantined.