Swiss Army Knife
A couple extra pair of strong shoe strings
About a square yard of fine netting
Small container of vitamins/minerals
Small lens or magnifying glass and a full cigarette lighter for making fires. Use the magnifying glass first whenever possible and conserve lighter fluid.
Container of superglue for closing smaller wounds
Commando wire saw:
https://www.amazon.com/dp/B000WDPGW2/?tag=pfamazon01-20 To cut poles for shelter as well as firewood.
The premise is: you have to survive 40 days, then you'll be rescued. No point in trying to find your way out. Just make camp and survive. It's summer and there's a stream, so dying of thirst or cold are not issues. Your biggest problems are going to be starvation and dangerous animals, especially bears.
256bits is right that a stream is not likely to have fish of any size, but, having grown up in New England, I know there will be guppy sized fish in small streams, and, if you're lucky, crayfish and frogs. That's what the netting is for. (Ignore salamanders in the woods there, incidentally, they are poisonous to eat.)
There should also be squirrels and chipmunks. Squirrels hang out in trees and chipmunks hang out in rock piles. Indians used to kill these with a throwing stick. That's nothing more than a stout stick about 2 1/2 feet long. The stick tumbles end over end after you throw it, which lessens how precise your aim has to be. Both squirrels and chipmunks are territorial and will hold their ground and chatter at you. If your aim is not too bad, you can also just kill them with rocks.
If you're lucky, you'll encounter a porcupine. They don't move too quickly and can be killed with a stick. And, as far as I know, the meat of any snake you can catch in that region is edible. Any small animal has intestines and these should be cleaned and dried for their function as cordage. They'll be like rawhide: stiff when dry, but soft after soaking.
Near the stream there might be fiddle head ferns, which are edible. If there are squirrels, there may well be acorns as well. Be aware: acorns have to be ground up and leached a few times to get rid of the tannic acid before you can eat them.
The smell of meat, cooked or raw, is what will really attract bears. I would adopt the policy of two camps: a cooking camp and a sleeping camp, at least a hundred yards apart. Don't bring anything edible to the sleeping camp.
If it rains, you're going to be miserable. Worst case scenario is you initially end up there right while it's raining. What you need to do to avoid catching pneumonia (wearing only a t-shirt, as was stipulated) is to push together as big a pile of forest floor litter as you can; pine needles, leaves, whatever, and then burrow into it. Despite being wet, this will afford you the most insulation. When I say "big" pile, I mean you want three feet or more of litter on top of you and some underneath to insulate you from the ground. You might think that crawling into a pile of wet stuff is going to make matters worse, but you will actually be more in danger of being roasted to death in there: wet organic matter massed up in piles actually heats up on its own and over time can spontaneously combust. Ask any farmer about storing wet hay: it's a fire hazard. So, you may actually have to get out and pull some of the matter off the pile to cool it down.
Thereafter, you're going to want to make a zoobie brush shelter for the next time it rains. With your wire saw, cut enough long poles to make a tipi like structure, then cover the outside with fir boughs hung upside down to drain the water away. You should be able to make lashing material for that by splitting thin, green branches and soaking them in the stream to make them more flexible. Might have to experiment to find the best kind. You leave a smoke hole at the top and you can have a small fire inside. (Obviously, don't do that when it's not raining and the fir boughs are dry.) Traditional Indian tipis are somewhat tilted: the smoke hole is not over the center of the floor where the fire is but is offset so rainwater doesn't drip right on the fire. The water drips on a spot between the fire and the door hole. Rough out a little drainage channel.
At night (or anytime actually) you can cover your head, at least, with the guppy netting to keep mosquitos off.
Ration out your vitamins. Your diet is going to be limited. The vitamins are a stop gap against any sort of deficiency that could take your edge off.
According to google there are plenty of birch trees in Canada. Birch bark is a great material. You can peel it right off the living tree: score the shape you want with your knife, lift up an edge and carefully peel the sheet off. If you fold over a large rectangle and lace up two sides, sealing them with pine pitch, you would have a sort of envelope for bring water from the stream to camp. Punch holes in the edges of the bark with the awl of your swiss army knife, and lace up with the shoe strings or squirrel gut, if you've been able to get one. If you prop that up, say between two rocks, you can make a fire and heat up some stones which you can drop into the water to heat the water.
People started out this way: living directly off the forest. It's absolutely doable, but you have to chuck all thinking about what modern tools you don't have and dig in and see what can be done with what's actually around you. If a person has water, they can survive three weeks without food. Your job is to somehow hunt/scrounge the minimum survival calories needed to keep you alive the full 40 days.
