12. C is for Carbon Monoxide

A mildly Covid-y Lorien tells Katharine how the first five minutes of one episode of ER scarred her for life. Sources https://www.analoxgroup.com/blog/carbon-monoxide-v-carbon-dioxide-do-you-know-difference https://www.cdc.gov/dotw/carbonmonoxide/index.html https://www.mayoclinic.org/diseases-conditions/carbon-monoxide/symptoms-causes/syc-20370642 https://www.texastribune.org/2021/04/29/texas-carbon-monoxide-poisoning/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5848400/ https://myhealth.alberta.ca/Health/Pages/conditions.aspx?hwid=hw193731 https://www.mayoclinic.org/tests-procedures/hyperbaric-oxygen-therapy/about/pac-20394380 https://www.careservicesinc.com/blog/how-to-tell-if-carbon-monoxide-is-leaking-from-your-furnace-in-falling-waters-wv https://getjerry.com/home-insurance/can-opening-a-window-stop-carbon-monoxide-poisoning