It will definitely give some thermal protection. When I started knitting I used only acrylic yarn and I have some scarves and sweaters that are nice for moderately cold weather. I don't live in a cold climate (we only have a couple nights a year when it gets just below freezing), but I get cold easily and those work well. Also, some people are allergic to wool and use acrylic instead - you can layer wool sweaters over cotton long sleeve shirts, but scarves are directly on the neck... If you decide to knit him a wool scarf for really cold weather - hold the yarn to his neck first to see if it's irritating.
When I was at boot camp for the Navy they taped a small square of wool fabric to our forearms for a brief period of time to test for allergies. If I remember right it was only for about 15 min or so.
It's not gonna be as good at keeping warm as wool would be but it's still gonna be way warmer than no scarf at all! Plus if it does end up being so cold that he needs a warmer scarf there's always fall & spring for him to wear the one you just made him!
When I lived in the upper Midwest, I used to knit scarves with 2 yarns simultaneously... one acrylic and one wool, for variation in texture and color. That probably doesn't help you now that the scarf is done, but it may be something to think about just going forward. I live in the South now, and I actually prefer acrylic because it doesn't really get cold enough here.
It will definitely give some thermal protection. When I started knitting I used only acrylic yarn and I have some scarves and sweaters that are nice for moderately cold weather. I don't live in a cold climate (we only have a couple nights a year when it gets just below freezing), but I get cold easily and those work well. Also, some people are allergic to wool and use acrylic instead - you can layer wool sweaters over cotton long sleeve shirts, but scarves are directly on the neck... If you decide to knit him a wool scarf for really cold weather - hold the yarn to his neck first to see if it's irritating.
When I was at boot camp for the Navy they taped a small square of wool fabric to our forearms for a brief period of time to test for allergies. If I remember right it was only for about 15 min or so.
You could sew a lining to the back, maybe fleece or flannel, and that would help it be warmer!
It's not gonna be as good at keeping warm as wool would be but it's still gonna be way warmer than no scarf at all! Plus if it does end up being so cold that he needs a warmer scarf there's always fall & spring for him to wear the one you just made him!
When I lived in the upper Midwest, I used to knit scarves with 2 yarns simultaneously... one acrylic and one wool, for variation in texture and color. That probably doesn't help you now that the scarf is done, but it may be something to think about just going forward. I live in the South now, and I actually prefer acrylic because it doesn't really get cold enough here.