Get cold a lot more frequently

When I work out hard and diet hard, I get cold, too. Then it's time to wash some dishes or drink some tea. I've never considered seeing a doctor about it.

I think it's normal; less body fat
Try lifting weight regularly
That seems to have helped me stay warmer

I'm always cold!

The winter after I got my breast reduction I could NEVER get warm. I'd be sitting at work with my space heater on top of my desk blowing on me. People would make comments and I'd just say "I don't have enough boob to keep me warm anymore".

And after losing weight over the summer I've been getting colder faster than I did before.

It's normal, for a couple of reasons: (1) You have less fat, which as others have mentioned, means less insulation. (2) People who lose a substantial amount of weight burn a little less energy than people at the same weight who haven't lost weight. It's called "adaptive thermogenesis," and probably results from less fidgeting or other semi-conscious moving around, since their bodies have been used to making do with less for quite some time.

If you're feeling really cold, or shivering, then see a doctor. Otherwise, you'll probably adapt to it. I was a lot colder last autumn than I am now, even though I'm 19 pounds lighter now than I was back then.

It's normal. You'll get used to it and adjust. Stay more active and your body will warm you up.

You'll also start noticing how very obese people turn the air conditioning as cold as they can because they're feeling hot all the time.

Normal. And depending on what you do, not undesirable. For high-output workouts, one "shutdown" mode for the body is heat management - if you get over a certain temperature threshold, your body makes you reduce the intensity.

Leaner people lose heat faster so they can exercise at high intensity longer.

Lost 101 pounds so far… ALWAYS. COLD. Always. I chalk it up to less insulation! I am dreading this winter!

Muscle tissue helps to keep you warm more than fat does. Fat insulates you, but muscle tissue generates heat. If you lose weight, you frequently lose both, hence feeling cold all the time. Loss of lean tissue such as muscle isn't good for health, so my advice is to try to regain some lean mass by working out with weights/strength training, and eating at a small surplus for a while. If you still have fat to lose, you can do a cut cycle after that (i.e. continue working out, but eat a little less than you burn off and ensure you get plenty of protein)

Doing more exercise and being more active makes you feel warmer and burns of calories.

I went from being obese to being lean, and I withstand the cold better now than I did when I was obese. Mostly because I have increased my lean mass. I have a high lean mass for my height (this is genetic) and never really felt the cold much anyway. I feel the cold even less now. I can be outside in a t-shirt in weather where everyone else is wearing a coat.

Don't accept it as inevitable that being lean means feeling the cold more. It's not inevitable. Focus on body composition, not just weight. Muscle tissue is like central heating. Fat is like loft and cavity wall insulation. If you've got less loft and cavity wall insulation, you need to turn the central heating up. And you'll burn more fuel doing so (i.e. burning more calories from food, because this is an analogy for the human body, not advice about how to heat your home)