I live in S. Calif. and bought these for chilly nights around 63 degrees.
My Mid-Weight Duofold were too warm, so I decided to try these. I'm very happy with my purchase, they are just perfect for a chilly night, yet not so warm to make me uncomfortable.

They are also not bulky therefore these can be used to wear as underwear when weather is colder.

Being 5'7" 165 lbs 33 waist I chose Medium which made a perfect fit. Not too tight, not too loose. The beauty of these are that the legs don't ride up while tossing and turning is bed.
Being 81% Poly 14% cotton and 5% Spandex gives these pants a soft feeling yet will not shrink in the wash as 100% cotton does. They very are light weight and very comfortable.
Excellent product and highly recommended if you like quality.

I spend much time looking for night wear and found that the price is very reasonable
and affordable in comparison.
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Additional Notes:
I love these so much I've been wearing them daily. So today I was going to order another. I find the price went up 50% that was disappointing, so I searched google
and found another place selling the same at $3.00 less plus 2 for one. Therefore it cost me less than $9.69 each plus free shipping, and didn't have to buy something else to make up the $25.00 free shipping offer.  It pays to search - 2 each for less than 1 costs here, plus no minimum to get free shipping. Sorry Amazon a 50% increase was too much for me.