Why Do We Get Fevers If Heat Can Kills Us?

It's 3 a.m. You're burning up at 39 degrees, yet you're shivering under two blankets and your body is begging for more heat. Heat can kill a human being. So why does your body deliberately turn up its own temperature the moment a germ gets in? In this video: how your brain's thermostat gets moved (and why that makes you feel freezing), the lizards, fish, locusts and even bees that give themselves fevers, the virus that evolved a weapon against fever, the Nobel Prize for treating one disease with malaria, why a fever almost never gets high enough to harm you, what really happens when you take a fever reducer, why having no fever can be the scary part, and why your normal 37°C might be a fever that never ends. Chapters 0:00 Freezing at 39 degrees 2:06 What a fever actually is 5:20 The price of a fever 6:53 The lizards that give themselves fevers 9:09 The virus that fights back 10:50 Does a fever cook germs? 12:28 What the heat really does 14:17 Why a fever almost never kills you 16:01 Fever phobia 17:16 Should you take the pill? 20:10 When no fever is the scary part 23:13 Why 37°C is a fever that never ends 26:29 Back to 3 a.m. This video is for general education, not medical advice. If you're worried about a fever, talk to a doctor or your local health service. Get help urgently for a baby under 3 months with a temperature of 38°C or more, or for anyone with a fever who is confused, very hard to wake, struggling to breathe, or has a stiff neck or a rash that doesn't fade under a glass. Sources Vaughn, Bernheim & Kluger (1974), Fever in the lizard Dipsosaurus dorsalis, Nature Kluger, Ringler & Anver (1975), Fever and survival, Science Bernheim & Kluger (1976), Science Covert & Reynolds (1977), Nature Ouedraogo et al. (2004), Oecologia Rakus et al. (2017), Cell Host & Microbe Evans, Repasky & Fisher (2015), Fever and the thermal regulation of immunity: the immune system feels the heat, Nature Reviews Immunology Kluger & Rothenburg (1979), Fever and reduced iron: their interaction as a host defense response to bacterial infection, Science Foxman et al. (2015), PNAS Mackowiak, Wasserman & Levine (1992), A critical appraisal of 98.6°F, JAMA Protsiv et al. (2020), eLife Mackowiak & Boulant (1996), Fever's glass ceiling, Clinical Infectious Diseases Hart (1988), Biological basis of the behavior of sick animals, Neuroscience & Biobehavioral Reviews Nesse (2005), Evolution and Human Behavior Schmitt (1980), Fever phobia: misconceptions of parents about fevers, American Journal of Diseases of Children Crocetti, Moghbeli & Serwint (2001), Fever phobia revisited, Pediatrics American Academy of Pediatrics (2008), Febrile seizures guideline Graham et al. (1990), Journal of Infectious Diseases Doran et al. (1989), Journal of Pediatrics Earn, Andrews & Bolker (2014), Population-level effects of suppressing fever, Proceedings of the Royal Society B Young et al. (2015), HEAT trial, New England Journal of Medicine Rumbus et al. (2017), PLOS One Norman (2000), Clinical Infectious Diseases Starko (2009), Salicylates and pandemic influenza mortality, 1918–1919, Clinical Infectious Diseases Robert & Casadevall (2009), Journal of Infectious Diseases Bergman & Casadevall (2010), mBio Casadevall (2005), Fungal virulence, vertebrate endothermy, and dinosaur extinction: is there a connection?, Fungal Genetics and Biology Casadevall, Kontoyiannis & Robert (2019), mBio Guinness World Records, Highest body temperature NHS, Fever in children; Sepsis #fever #science #biology #health #didyouknow