I read different take on that. There is a recent hypothesis that humans has a budget of energy that is spent each day independent of calorie intake, like 2500 kkal for a male, unless the body switches to the starvation mode with persistent multi-months calorie deficit.
If one does not do a physical activity and does not spent energy to warm the body, the body instead spends that energy budget on various expensive activities like synthesis of hormones (like testosterone for males) or to activate immune system more than necessary leading to asthma. But immune system for normal function does not require much energy and as long as one eats enough, the persistent cold exposure should not affect it.
If one does not do a physical activity and does not spent energy to warm the body, the body instead spends that energy budget on various expensive activities like synthesis of hormones (like testosterone for males) or to activate immune system more than necessary leading to asthma. But immune system for normal function does not require much energy and as long as one eats enough, the persistent cold exposure should not affect it.