Huh. I don’t know if I’m picking up what they’re putting down here, but it kind of sounds like suppressing fever e.g. with Tylenol would actually be bad for (normal) flu progression.

Fever helps against all kinds of illnesses but it can also be deadly, so having fever reducting medicine around is a smart precaution IMO. If you're otherwise healthy and are dealing with a mild seasonal infection and have got something important going on, I can see why people would choose to reduce symptoms at the cost of taking longer to recover.

Lots of people go overboard with this, though, like taking flu reduction medicine with every single cold or using medication to go to work sick. American media seems especially accepting of people taking "flu medicine" over rest and recovery.

Copying Google AI's response here as it's at least as good as what I was going to recall:

> Fever is a key part of the innate immune system, acting as a protective response to infection by raising the body's temperature. This increase in temperature inhibits the growth of many pathogens, enhances the activity of immune cells like leukocytes, and improves the effectiveness of the adaptive immune response.

My Vietnamese in-laws commonly make a sweat tent to shorten the duration of sickness. I can't say if it works, but it's something I intend to try next time I'm sick.

Well, yes?

Very simplified... It is a suppressor of symptoms like pain and fever which are the bodies way of letting you know something is damaged and killing off unknown foreign bodies respectively.

Suppressing symptoms does not remove the cause and is not a cure.

It's a fairly common notion to "sweat out" a flu. Stay in bed, wrap yourself up in lots of blankets and just sweat the damn thing out. High body heat kills the virus.

So it would make sense that drugs like tylenol/paracetamol would make you feel better, but would keep the flu alive in you for longer.

It is, as others have pointed out.

Although, we’re very unusual humans in the grand scheme of things. So using medication might be reasonable. The brain might start taking damage around 104F. That was probably a good tradeoff for a peasant farmer (our ancestors, on average). Most of us nowadays just think for a living, not such a good tradeoff for us. Take the fever suppressant, what’s the worst that’ll happen if you miss an extra day of work?

Our pediatrician didn’t want us to give Tylenol unless the fever was over 99.5 and not to bring them in unless it was over 101 with Tylenol.

You want your immune system to simmer, not to boil.

It may go further than that:

> Fever is used by organisms as diverse as fish, amphibians, reptiles and mammals (see for reference Basu and Srivastava, 2003). Since fever is metabolically expensive, it must provide substantial advantage to the host. Surprisingly little is known about immunological effects mediated by fever, a lack of understanding that might be attributable in part to the common ignorance in clinical practice with respect to benefits fever might provide. Post-operative infections can be prolong survival: patients developing empyema after lung cancer surgery have improved 5-year survival (50% (n = 18) vs 22% (n = 411)) (Ruckdeschel et al, 1972). In this light, it seems unfortunate that fever is usually suppressed in hospital routine.

> The phenomenon of spontaneous regression and remission from cancer has been observed by many physicians and was described in hundreds of publications. However, suggestive clues on cause or trigger are sparse and not substantiated by much experimental evidence. [...] At least in a larger fraction of cases a hefty feverish infection is linked with spontaneous regression in time and is investigated as putative trigger.

> Professor Busch in 1868 introduced the infection of cancer patients by purpose as a novel strategy to treat cancer. He achieved a dramatic regression with his first patient using live Streptococcus pyogenes bacteria, the pathogen leading to erysipelas, published in the German Journal ‘Berliner Klinische Wochenschrift’ (Busch, 1868). Beginning in 1891, this strategy was exploited by Coley, who had some reading knowledge of German (Hall, 1998). Coley systematically applied Streptococcus pyogenes extracts – later called ‘Coley’s toxin’ – to cancer patients and achieved a remarkable rate of regressions. A retrospective compilation of cases considered inoperable at the time of treatment between 1891 and 1936, which was conducted by Wiemann and Starnes (1994, Table 2), determined a remission rate of 64% (108/170) and a 5-year survival rate of larger than 44%. Coley used to inject his extract once or twice a week over a period ranging from a few weeks to several months. His method became quite famous and was tested on hundreds of patients by him and contemporary physicians, but overshadowed by the development of X-ray treatment which was regarded to be much more powerful and of broader applicability.

> Since cancer is usually a slowly progressing disease with occasionally long periods of dormancy, putative beneficial fever effects should also precipitate as preventive efficacy. This can indeed be found. In a cohort of 603 melanoma patients compared to 627 population controls, an inverse correlation was found between melanoma risk and number of recorded infections on the one hand and between melanoma risk and fever height on the other hand, leading to a combined reduction of melanoma risk of about 40% for people with a history of three or more infections with high fever above 38.51C (Koelmel et al, 1999). Mastrangelo et al (1998) report a striking inverse correlation between the number of infections and mortality from tumours in Italy in the period 1890 –1960: every 2% reduction in the number of infectious diseases was followed by a 2% increase in tumours about 10 years later.

https://www.nature.com/articles/6602386.pdf

https://pubmed.ncbi.nlm.nih.gov/16444847/

I know someone who doesn't get fever. When he gets sick with regular cold or fly it's much longer and worse than for anyone else I know.