We'll second that as if the humidity where humans are living in drops below 30%, noses and throats dry and often get scratchy feeling and sore like a sore throat cold and our lips start cracking. Below 20% a nose will even crack inside and bleed and a very big reason we stay away for deserts and the southwwest. Everytime we've gone to those dry air areas, she has to turn on the small high intensity humidifer we take along and breath the wet air in deeply a while every hour or two. Sleeping in the dry air is miserable! It also helps me a lot staying out of the dry air too but staying out of those areas eliminates the problems entirely.
My wife's fingers also get splits near the ends in dry air and bleed and she has to use a special very expensive prescription ointment applied to them every couple hours. The dry air nose bleeds are even worse. Takes 4-6 days for her fingers to heal enough so she can even touch things with them without real sharp pains. They never split when in above 30-40% humidity and I breath so much better too.
Putting decently sealed storm windows on inside virtually eliminates window sweating, other sweating, or even ice inside when it's -10 F outside and you only need to vent the cooking moisture while cooking out. In a very amall camper with 2 people inside, crack a roof vent 1/4" for an hour 2 times during each 24 hour day. Any heat escaping carries most of the moisture inside out with it. Heat always naturally rises! Every time you open the door fresh drier air rushes in and further lowers the relative humidity inside. You learn to keep the humidity level comfortable real quick!
