I would recommend taking a fleece.
NOTE: Most brands of Polar-Tech type fleece come in three distinct weights or thicknesses. Polar -Tech is the first brand invented in the 1980s, and is the generic term used to describe the poly fleece fabric, usually made from recycled plastic bottles. Some better brands still use this branded fabric. look for it on labels and in product descriptions.
You can tell the difference in weight or level by touch. The weights are referred to as 100, 200 and 300 level or weight. Sometimes the weight factors into the style name, or appears somewhere in the description.
However, if you have several different fleece garments of the same type *(e.g. a jacket or pullover) pinch the sleeve and slide two fingers to gauge the thickness of the material. You can readily feel the difference from levels 100 to 200 to 300.
I recommend using level 100 in the spring - early fall for someone who does not chill easily - like me. For someone who does get chilled easily, or if you plan to use the fleece in lieu of a sleeping bag, I recommend 200 to 300 level fleece.
If one is walking from late September through April, I recommend going up a notch to using 200 - 300 level fleece for all.
I use level 100 or 200. As a large fellow, who prefers to be a little cool, and who does sweat profusely, I prefer going no higher / thicker than level 200. For reference, in May I obtained a level 100, full-front zip, fleece from Decathlon in Santiago for €9,99. It was on their hunting aisle. While not branded Polar-Tech, it is nonetheless excellently made and provides excellent value for cost.
Hope this helps.