One of the great things about the Icy Embrace of Winter is that it introduces environmental dangers to an otherwise perfectly hospitable and safe region. The complications caused by these dangers add difficulty to an otherwise normal situation and create a sense of urgency since prolonged exposure to the elements can cause injury or death. Most of the dangers can be mitigated with preparation and technology, but even a modern society can buckle or break down under severe weather conditions.
Here’s a checklist of environmental conditions to consider in a winter scenario:
Snow: The most obvious one. Snow can make travel difficult and even block access to some locations entirely. Even in a modern setting, roads could be uncleared, making access to – or escape from – your adventure locale difficult or impossible. Buildings can be damaged or even collapse under the weight of accumulated snow. Snowfall reduces visibility and can covert tracks, making wilderness orienteering harder.
Ice: Lakes and even rivers can freeze over completely; this allows people on foot, or maybe even horse or car, access to locations they couldn’t go before, but it blocks travel by boat. Ice can be a hazard to shipping even if it’s not a continuous ice cover – famously illustrated by the fate of the Titanic. On land, ice can make roads or other terrain impassable (because it’s slippery) and it can damage or destroy infrastructure.
Wind: Storms and snow can combine to create blizzards. Without protective goggles, this can further reduce visibility – to the point of being essentially blinding. Wind also causes snow drifts and can shift snow into otherwise sheltered places. Wind chill will enhance the effects of low temperature on animals and humans by increasing the rate at which their bodies cool down. And of course, high winds can cause further damage to infrastructure by themselves.
Cold: Prolonged exposure to extreme cold can cause hypothermia and frostbite. Elderly people and infants are more susceptible than adults. Temperature below freezing can damage vegetation, and thus destroy harvests if it’s unseasonal. It can cause pipes to burst. If a city depends on an external source of fresh water – for example brought in by Aqueduct – this can complicate life, though the citizens can always melt ice and snow for drinking water. Remember that cold is relative; a society in a Mediterranean or tropical climate is less prepared to deal with cold than people who live in subarctic regions.
Frostbite: Damage to body tissue caused by cold. A wind chill of -30C will cause frostbite in 30 minutes. Frostbite causes loss of feeling in and a white or pale appearance of fingers, toes, ear lobes or the nose. Extreme frostbite can cause these to essentially die, requiring amputation. It’s not pretty and presumably not something you wish to inflict on your protagonists; but there are always side characters/NPCs.
Hypothermia: If a person’s body temperature drops below 35°C, it can eventually kill. Survivors may still experience lasting damage to internal organs. Warning signs include shivering, memory loss and disorientation, and incoherence. Victims will also appear drowsy and exhausted. This is probably more suitable for a protagonist or player character, and, as it increases the difficulty of regular tasks, much more likely to add drama and tension to a situation than frostbite.
Creatures: In a more fantastic or science fiction setting, winter may bring creatures to inhabited lands that do not normally venture there – The Wendigo, Yetis, ice elementals, or even white dragons. Such creatures may actually also be beneficial, since sources for food are scarce in winter, and their fur or scales may be a valuable commodity.