G'day
Colds are attacks of an infectious disease (caused by rhinoviruses). The only way to catch them is from another person who is infected (either directly, by droplet, or (surprisingly often) from touching your mouth or nose with hands that have touched something that sick people have touched with dirty hands that have touched their mouth or nose). There are often epidemics of colds during cold wet weather, because in cold wet weather people tend to stay inside, close to other people, and so it is easier for the infection to pass from person to person. The cold and wet do not themselves cause colds, and on the contrary people in certain professions that expose them to cold and wet (such as sailors, fishermen, hunters, ...) tend to suffer fewer colds than other people, because those professions keep them away from other, infectious people during the epidemics. It is a myth that getting cold and wet will cause a cold.
But your D&D characters are not living in the real world, but in a fantasy world where myths are true. By all means give them colds if you want to.
However, it might be best to warn your players that colds and flu are in fact caused by infection, not by getting cold and wet. Because respiratory infections are responsible for something like 75% of all days of work lost to illness, and (according to the New Scientist recent field trials (in a US Army battalion in barracks ordered to wash their hands five times per day) have shown that respiratory infections can be reduced by 70% if people keep their hands clean.
The evidence suggests that if you give up on old wives' tales (and instead practice scrupulous cleanliness) you can reduce the number of day's work you lose to sickness by up to 50%.
That's right: at least half of all days' work lost to sickness in the USA can be attributed to careless hygiene, carelessness that is directly attributeable to superstitious belief that cold and water cause diseases that are in fact caused by viruses. You wouldn't want to be responsible for perpetuating a superstition that causes half of all debilitating sickness in the US, would you?
Regards,
Agback
Colds are attacks of an infectious disease (caused by rhinoviruses). The only way to catch them is from another person who is infected (either directly, by droplet, or (surprisingly often) from touching your mouth or nose with hands that have touched something that sick people have touched with dirty hands that have touched their mouth or nose). There are often epidemics of colds during cold wet weather, because in cold wet weather people tend to stay inside, close to other people, and so it is easier for the infection to pass from person to person. The cold and wet do not themselves cause colds, and on the contrary people in certain professions that expose them to cold and wet (such as sailors, fishermen, hunters, ...) tend to suffer fewer colds than other people, because those professions keep them away from other, infectious people during the epidemics. It is a myth that getting cold and wet will cause a cold.
But your D&D characters are not living in the real world, but in a fantasy world where myths are true. By all means give them colds if you want to.
However, it might be best to warn your players that colds and flu are in fact caused by infection, not by getting cold and wet. Because respiratory infections are responsible for something like 75% of all days of work lost to illness, and (according to the New Scientist recent field trials (in a US Army battalion in barracks ordered to wash their hands five times per day) have shown that respiratory infections can be reduced by 70% if people keep their hands clean.
The evidence suggests that if you give up on old wives' tales (and instead practice scrupulous cleanliness) you can reduce the number of day's work you lose to sickness by up to 50%.
That's right: at least half of all days' work lost to sickness in the USA can be attributed to careless hygiene, carelessness that is directly attributeable to superstitious belief that cold and water cause diseases that are in fact caused by viruses. You wouldn't want to be responsible for perpetuating a superstition that causes half of all debilitating sickness in the US, would you?
Regards,
Agback