Body Temperature (Fever Check)

The thermometer reads 37.8 C and the argument starts at home: is that a fever yet or not? Much of the confusion comes from having learned that fever means anything over 37, while most protocols only use the word from 37.8 or 38 upward. That leaves a grey band in the middle nobody knows how to name. You type the number here and the page hands back the band it falls into.

Under the hood there are four fixed cutoffs, all in Celsius: below 35 is hypothermia, 35 to 37.4 normal, 37.5 to 37.9 low-grade fever, 38 to 39.4 fever, and 39.5 up high fever. Each test is strictly less-than, so exactly 37.5 already reads as low-grade. Note that the normal band is wide and swallows 35.2 C, which is genuinely low for an adult, and nothing warns you at that end. Labels come out in Portuguese, with Febricula meaning low-grade fever.

Check two things before trusting the result. The value has to be in Celsius, because there is no Fahrenheit field. And the measurement site shifts the reading: an armpit temperature usually runs 0.3 to 0.5 C below rectal or tympanic. The cutoffs are adult cutoffs and do not adjust for infants or older adults. Treat the page as a reference ruler, not a diagnosis, and get care for fever with a stiff neck, breathing trouble or confusion whatever the label says. It all runs in your browser.