I lost the exact same amount of weight - about 17% to 18% of body weight - at the end of 2021* and I totally had issues with maintaining (mostly extremity) warmth. This was the end-ish of the pandemic, and I started dating again after that 2020 dry spell. Lot’s of al fresco dining because masks, and I froze my ass off.
Posted upthread, check Amazon for fingerless gloves. I love mine - I can use the mouse and still warm my hands. Outdoors you feel like an idjit but you get over it.
*And then regained almost all of it after herniating a disk, then having a DVT that turned into a pulmonary embolism and generally living unhealthily. I’m determined this time to keep the weight off, but this shit isn’t helping.