Calorie restriction is another possible way of lowering core temperature, and so anyone using this method in a life extension programme would automatically achieve benefits on the hypothermia front as well. There are, as indicated at the start of this chapter, still other ways of lowering our internal temperature, and these have been employed by Yogis for centuries.

Meditation and similar techniques
Here are some examples of how the mind can be used to control body temperature:

1. Impressive demonstrations have been given by people using deep relaxation/meditation methods which produced drops of internal temperature of a degree or more.

2. People wishing to learn to control aspects of body function have for many years used a 'high-tech' version of meditation, biofeedback, to produce effects such as lowered blood pressure, or increased or decreased temperature of body parts (hands made warmer at will where circulation to the limbs is poor, or the head made cooler in response to an impending migraine, are common examples).

3. Techniques currently widely employed to help induce deep relaxation, and which have highly desirable effects on immune function, such as autogenic training, use visualization of alterations in temperature as part of their methodology, with measurable differences in temperature being evident after only a short time.

There is no reason why these and similar techniques could not be investigated more closely to see how they could be modified to produce general hypothermia, and some examples will be found in the section on strategies.

Overview
We have now come to the end of the section which looks at the evidence for life extension through different approaches. One theme runs through all approaches, and this is dietary restriction, which seems to influence metabolic rate, body temperature, immune function, growth hormone and free radical activity - all for the better.

In the section on strategies which follows, dietary (calorie) restriction will be the dominant approach outlined. Along with this will come methods suggested by the various chapters on other alternatives, including stimulation of growth hormone production, anti-free radical tactics and ways of influencing core body temperature downwards. None of these is a recommendation. Rather, they are provided for information only, and any decision to use them should be accompanied by suitable professional advice.