Weather

[Sanjuro]

In severe cold, anything with an engine (or lots of moving parts) suffers from its lubricants freezing up. Modern engine oils have a bigger temperature range than they used to, but traditionally bush pilots in Canada and Alaska used to have to drain the oil from their engines overnight, then heat the oil over a fire in the morning. When the oil was hot, start the engine without any oil (this may also require heating the engine- yep, another open fire near vulnerable components) and immediately add the oil before the engine seizes up.
If equipment is matched to the climate it is used in, this problem can be mitigated (to an extent) by using the correct grade of oil, but if you are using vehicles originally planned for another deployment, or if supplies are rerouted...
To game the process of restarting cold-soaked gear, perhaps an encounter roll as the noise and heat involved attracts attention?