Fever Slows You Down and Wakes You Up: Data

Heart health
October 27, 2017

Running a fever can make you feel pretty crummy, but elevating your body temperature is actually the immune system’s way of fighting an infection. It’s important to rest during this process, and data from Thermo users reveals that this is exactly what people attempt to do—with mixed results.

A lack of energy often accompanies fever, but busy lives don’t always afford the opportunity to slow down. However, when examining data from users of the Thermo thermometer who also track their steps, we found a clear pattern: When individuals are fighting a fever, they log much lower step counts.  

Based on the four countries that we examined—the US, Germany, France, and Great Britain—users logged activity levels 75% lower on average when running a fever. The greatest disparity is found in France, where the average step count for those with a fever was just 490, which is almost 89% lower than the average step count when users don’t have a fever.

On the other hand, in the US, those with a fever don’t seem to rest quite as much. The average daily step count during a fever was 1341, which is only about 63% lower than the step count when healthy.  

Speaking of rest, getting a good night’s sleep is also key when sick, but unfortunately, it’s not the easiest feat to achieve.  

Among Thermo users who also track their sleep with a Withings device, the number of wake-ups during the night increased by an average of 50% when they had a fever, from 3.2 to 4.8. However, once again, the disparities vary by country. Users in France experienced an average of less than one additional wake-up per night when running a fever, while those in the US experienced almost twice as many wake-ups when they had a fever than when they did not.  

It’s interesting to note that over half of these users are parents with children, which may explain the relatively high number of average wake-ups even without a fever. Even so, having an elevated body temperature seems to lead to even more difficulty sleeping through the night—and this effect may be amplified as the illness makes its way around the house!

Because of the higher number of wake-ups, these users also spend more time awake during the night when they have a fever, with an average of 65 minutes spent awake during sleeping hours, compared to an average of 35 minutes spent awake during the night when not running a fever. Here too, users in the US demonstrate the largest disparity, with more than twice as much time spent awake during the night when they have a fever than when they do not. 

What Can We Conclude?

Our data shows that when Thermo users have a fever, they tend to walk a lot less. However, they also experience a decrease in sleep quality, with an increased number of wake-ups and time spent awake during the night, which might mean less rest than usual overall 

The Bottom Line

Taking it easy when you have a fever is a good idea, and while sleeping through the night may prove more difficult than usual, keeping your bedroom dark, cool, and quiet can help. 

And while avoiding all illness isn’t possible, there are a few precautions you can take to help prevent coming down with a cold, the flu, or any other nasty virus. Check out our guide below.  

We wish you good luck making it through cold and flu season healthyrested, and fever-free! 

Study Methodology

This study was conducted by Withings based on anonymous data from a pool of Withings Thermo Smart Temporal Thermometer users, 12,700 of whom tracked their activity and 4,700 of whom tracked their sleep. Withings guarantees the confidentiality of personal data and protects the privacy of all its users. Therefore, all data used in this study is anonymized and aggregated.