Counting from the hour the fever stopped
Enter the date and time your fever stopped and the page marks when 24 hours have passed, shown as a US-style date with a 12-hour AM/PM time. Whether a return time is issued then depends on two further answers: whether you are still taking fever-reducing medication, and whether symptoms are mild and improving. If either condition fails, the page names the one that failed instead of giving a time. Midnight, month ends and leap days roll over correctly.
The framework comes from the US Centers for Disease Control and Prevention in March 2024 (as of October 2026). The five-day isolation recommendation for COVID-19 was withdrawn, and the guidance moved to this: once you have gone 24 hours or more without fever and without fever-reducing medication, and symptoms are mild and improving, there is no need to stay home. Five days of added precautions follow, such as masking, distance and ventilation. The framework applies across respiratory viruses including COVID-19, influenza and RSV.
No table of incubation or isolation periods by disease is offered here, because those figures are described differently by different countries and agencies and are not confirmed as one set in an authoritative source. This page covers the US respiratory virus framework only, so where a school, workplace or care facility sets its own rule, or where local guidance differs, follow that instead. Shortness of breath, chest pain or a fever that returns are reasons to seek care. This result is not a medical diagnosis.
Frequently asked questions
Those periods are described differently by different countries and agencies, and no single set is confirmed in an authoritative source. Rather than build a table, this page works only from the framework the US Centers for Disease Control and Prevention applies across respiratory viruses.
No. The benchmark is 24 hours or more without fever and without fever-reducing medication. If you select that you are still taking it, the page reports the condition as unmet and does not calculate a return time.
They are for added precautions such as wearing a mask, keeping distance from others and improving ventilation. The period exists because transmission can continue after the fever has gone and symptoms are improving enough to leave home.