There are some changes that can happen in an organism over a short period of time to help them adjust to some changes in their surroundings. For instance, if we live in the plains and suddenly go to high mountain regions, we may
experience difficulty in breathing and doing physical exercise for some days.
We need to breathe faster when we are on high mountains. After some days ,our body adjusts to the changed conditions on the high mountain. Such small changes that take place in the body of a single organism over short periods, to
overcome small problems due to changes in the surroundings, are called acclimatisation. These changes are different from the adaptations that take place over thousands of years.