Today I found myself at the LGS once again. I found a copy of the AD&D 1st Edition Wilderness Survival Guide for five bucks.I was all set to buy it, but then I cracked it open. "Optional Rule: Relative Humidity."
Paging through it, my perception of the book is that it is a heap of random crap to screw the players with. None of it is particularly devastating, just tedious and, in my opinion, a little spiteful. Yes, all these elements are realistic. Yes, it's harder to start a fire in certain climates. Yes, food might spoil or humidity might affect you... but the book struck me as nothing more than a hindrance to the player characters. I could find absolutely nothing in the book that did not bog the DM down with tedious administrative duties related to the local climate, and saddle the players with a bunch of additional penalties for things.
I did, however, buy a copy of "The Red Mausoleum", a module that is touted as being specifically being compatible with OSRIC. I am in the process of reading it so far, and I do enjoy it. I think it was money better spent than if I had picked up the aforementioned Book of Irritating Penalties*.
*Yes, I know some of you like to bitch slap your players because they didn't bring enough blankets, or because they shouldn't truck around in their metal armor all the time, and I respect that. Hell, I've heaped woe on plenty of player characters who wander around with obvious gaps in their preparation. However, I just don't see what a book of fire starting probabilities and information on the mechanical effects of humidity is going to do but slow me down or be forgotten when I'm in the heat of the DMing moment.