If we're going by 1e RAW, low Con for one night doesn't matter much because disease checks are done once per month (or once per week in "VERY HOT WEATHER OR HOT, MOIST WEATHER" or "FILTHY, CROWDED CONDITIONS IN WARM WEATHER"), as well as each time a character is exposed to a carrier. Con scores don't affect the likelihood of contracting a disease*, only the severity and chance of becoming a chronic disease.Nah. Sick germs would be all over the party, the places they sleep, cities, dungeons, the outdoors, already in their bodies being fought off successfully, etc. Even going right to sleep would often mean bad news.
Fantasy worlds are not clean places. Hell, even in the modern world where we know what to do, infections/sickness hit hospital patients often. And they have higher cons in cleaner places.
And it's not a house rule. You get con back at a rate of 1 per 6 turns unless you go unconscious. If you go below 3, full con is restored 24 hours later.
*If the initial roll indicates disease is contracted, you roll a d8 for both occurrence and severity. A Con of 10–12 gets a -1 on both rolls, a Con of 3–5 gets a +1, and a Con under 3 gets a +2. If either modified roll is 0 or less, the character doesn't actually contract the disease, so a Con or 10 or higher does reduce the likelihood of disease to some extent.






