Personal water filtration
One thing to always consider is how you are going to get drinking water. If you are stuck in the wilderness more than a day or 2, and develop diarrhea due to impure water, you are likely to die.
I am retired from the Army, after 32 years, and have served in both infantry, and armor, in combat, in 3 wars. I also am a paramedic, and registered nurse. I have used water purification tablets, which are basically iodine, as well as boiling. Both methods are satisfactory, but less than perfect.
Iodine tabs make the water taste awful, tend to make me nauseated, and don't always kill all of potentially harmful microorganisms.
Boiling obviously requires a fire, a suitable container, and takes a long time. Filtration is a quicker method, and has the added advantage of removing particulate debris. I always carry a filter straw in my pocket when I am anywhere in the wilderness, even on short nature hikes in a park.
My preference is the Aquamira Frontier. It is an activated charcoal system that will filter 99.9% of microrganisms, and also some chemical contaminants as well. It is small to easily fit a pocket, and light, weighing less than an ounce, and inexpensive - only a few dollars.
I have used one a lot to drink from streams when camping, and have never gotten sick. I keep several in my emergency kit.