Overall App Summary:
Fever Meter purports to allow users to input a pulse (heart rate) and utilize the app’s algorithm to calculate their body temperature. The limitation here is that there are no current formulas or data supporting this process, and with a developer that does not identify their background (e.g. medical experience) or supplies any transparency or validation data, this app becomes even more suspect. Patients looking for a quick way to use their smartphone to measure their temperature will have to settle for new digital tools that use devices that directly connect to their phone or use Bluetooth enabled connections to measure and record body temperature. No clinician should recommend this app, and no patient should trust it for themselves or others. The app (as well as the Spanish language version, iFiebre) should not be used and should be removed from the app store.
App’s Intended Use:
The FeverMeter app is intended to provide users a thermometer free method of measuring and calculating their body temperature based off their self-measured pulse. The user must “calibrate” the app with a baseline heart rate and temperature and can then enter their current heart rate to get an estimated temperature. This formula is not accurate and the app should not be used to measure a patient’s temperature.
Who’s this app most useful for?
Patients seeking to measure their temperature that do not have access to a traditional method (e.g. thermometer).
How should one use it?
This app should not be used by patients. It should be removed from the app store.
Why should anyone use this app? Is it clinically relevant?
This app is not clinically relevant and lacks any scientific evidence that it works. During evaluation of the app, we tested the app multiple times with personal self measured pulse and theoretically pulses that yielded results that did not clinically make sense (e.g. 80 beats per minute = 67.1 Degrees F, 120 beats per minute = 88.7 Degrees F). The app also relies on a user to self measure their own pulse and then use the app to calculate the temperature. However, the method of calculating temperature does not appear correct. No patient or clinician should use or trust any data from this app.
Is there any published evidence that the app actually works?
No. While there is some literature on using heart rates to estimate temperature; (http://www.usariem.army.mil/index.cfm/modeling/cbt_algorithm), this app does not disclose or identify anywhere in the app or developers ‘website’ its algorithm, nor are any validation data available. Our use shows that the app does not accurately measure temperature and is misleading for patients.
Not FDA cleared, but likely required under Mobile Medical Applications guidance.
What is the most important/ desirable feature of the app?
None. This app still requires rigorous scientific validation.
How would you compare this app with others in its class?
This app, and others that purport to calculate temperature from pulse, should be disregarded. Patients would benefit instead from a Bluetooth enabled device paired with their smartphone.
If there’s a paid version, is it worth the upgrade?
Security and Privacy