I’m sorry for missing Monday, I needed the day off, as we all do sometimes.. Even our characters get busy and run-down, and have to take a day off.
In the real world when you’re feeling a little under the weather, you can call in sick. When you’re a hero tasked with saving the world, there are no sick days, holidays, or mental health days; team evil never takes a vacation. In fact in most games, like a comedy-drama tv show, the plot happens to the characters. If they win a week at an Elvish spa, the local orcs will choose that time to invade!
One saving grace is that the rules of D&D don’t allow for getting sick naturally. Or if they do, I’ve never of a campaign playing with those rules. So, feel free to send you characters outside in the cold without gauntlets and helm! Or have them lick random strangers, drink the water, and eat the street food. The assumption the only way to get sick is from being diseased or poisoned.
In the olden days you either needed a 1st level Paladin or a mid-level cleric spell to undo a disease. Now through a series of Endurance checks (which can be superseded by Heal) a hero can recover on his own with some bed rest. Of course, it’s probably more likely that waiting it out will worsen the condition, but the actual risk will depend on the disease. Think of this series of necessary extended rests to get cured up as if it were going on heroic short-term disability. If you don’t want to wait, the health care in the Nentir Vale is better than in the US. It’s only 150gp and a 6th level ritual to Cure Disease and get your character up and running again in no time (well, in less time than it takes to get a pizza).
As frightening as diseases are, thankfully we no longer have to worry about level drain! So while disease-causing monsters are bad news, with some precaution, old fashioned bed-rest, or magic, it doesn’t have to be fatal.