For any given substance, the heat capacity of a body is directly proportional to the amount of substance it contains (measured in terms of mass or moles or volume). Doubling the amount of substance in a body doubles its heat capacity, etc.
Conventional soft contacts can last up to a year; conventional rigid gas permeable (RGP) contact lenses can last even longer. Frequent or planned replacement contact lenses last one to several months. Disposable contacts last from one day (daily wear) to up to two weeks (extended wear).
Many people take longer to get used to rigid contacts than to soft. It will probably take about 2 weeks to become accustomed to these lenses but could take 3 weeks or more. You can ease into wearing them by starting at just a few hours of wear per day and increasing by an hour each day.