Is it normal blankets no longer warm me?

I'm going to be original, (since everyone just keeps telling you to buy new ones) and tell you that you should buy new ones.

Very simple. And I want you to take notes. You ready? Okay. First of all you need to hook up with a fat Chinese girlfriend. One with a nice big pot belly. Now for dinner every night you need to tell her that you want her to make some hot and spicy fried rice. Only say it like: Me want flied lice! Me want flied lice! That way she's sure to understand you if you speak in her native tongue. Now be sore she adds lots of garlic, onions and red and green peppers so the "flied lice" is hot and spicy. At bed time make sure to cover the blankets over your heads. That way when you both start blasting away with your incredibly loud farts the trapped air under the blankets will keep you both nice and toasty warm. Oh, one other thing. You may consider wearing a gas mask. Okay, got that? Just refer to your notes if you forget any of my instructions. :-)

Get a thicker one. Try blankets made out if wool or goose feather stuffed. Now, if you are constantly cold and this is new for you, you might want to see a doctor.

Go to the doctor and ask for a blood test to check out your thyroid function.

Do some exercise to warm yourself up.

Buy a thicker one, stack blankets on yourself, or wear something warm.

Buy new and better ones.