I have a science background and get into arguments with people about common colds and fevers. I argue that they are caused by viruses and bacteria, which go from organism to organism. using this example from Encyclopaedia Britannica about polar expeditions:
In contrast, members of scientific expeditions have spent whole winters in the Arctic or Antarctic without any respiratory illness, only to catch severe colds upon the arrival of a supply ship in the early summer. This is because viruses, not cold temperatures, cause colds. During polar expeditions, the members rapidly develop immunity to the viruses they bring with them, and, throughout the long winter, they encounter no new ones. Their colds in the summer are caused by viruses imported by the crew of the supply ship. When the members of the expedition return on the ship to temperate zones, they again come down with colds, this time caught from friends and relatives who have spent the winter at home.
It does not convince them. They argue that one can catch a cold from temperature changes, going outside with wet hair, or air conditioning in a car alone. This happens even with medical doctors. I asked them for evidence and they do not provide it. Although the covid pandemic has shown that viral infections spread from person to person, they usually do not make the parallel with the common cold.
I know that temperature changes can cause physiological illness, such as heat stroke or frost-bite, but here my focus is day-to-day environment in a temperate European climate.
What is the evidence for temperature or humidity causing respiratory illnesses, common cold, fever, sore throat, cough? If it does not exist, how can I convince them otherwise?