“I used to feel very cold right after meditation and its winters”
– Is it because it is Winter?
It is also possible that one’s body responds to meditation with one becoming cold, thirsty, sweaty, frozen, etc.
– Those can be good signs indicating that the body can feel the effects of meditation.
In any case, one needs to take appropriate actions to remove any discomfort.
For example, wear something warm, drink water, turn on cooling correspondingly. If one’s body becomes “frozen”, one can just get up and do a walking meditation.
– There is no need to sit like a statue in any of those cases. Getting up to drink water will not disturb an “effective samadhi.”
– One can do mediation in all four postures (sitting, standing, walking, and lying down).
The ultimate goal of meditation is to cultivate Panna (wisdom) and realize the unfruitfulness AND dangers in the rebirth process.