BTW, threads like this are very fun exercises that can really get you thinking about survival! Choosing four items is arbitrary, and anyone that hangs out at ETS will hopefully be better prepared than that, but it does help focus priorities.

In my mind a tent would be huge! Obviously a lot camper might have a tent along already as part of their normal load out but otherwise it's bulky enough that almost no one would carry one "just in case". That said, I think having a tent is huge psychologically. Being in a tent does feel like being indoors, making one much more comfortable in strange surroundings. A good test provides a lot of protection, too. It offers protection from the elements (keeping you dry) and protects from convective cooling (the wind blowing on you). It won't hold in a lot of heat but it will prevent many kinds of heat loss. Great for keeping the direct sun off of you, too.