Hardening should be carried out systematically. All kinds of hardening cannot be done with under fasting condition and before 1 hour after meals.
A greater effect is achieved with a combination of several types of hardening: taking air baths, gymnastics with effusions, rubbing, balm and massage. People prone to colds, should do systematic ablutions of the feet at bedtime, followed by rubbing with a towel and massage till the skin redness. First time the temperature of water should not cause irritation (approximately 18C), and you should gradually reduce it. This procedure can be started only in a healthy condition.
Among the preventive hygienic measures that contribute to the activity of the larynx, a larynx douche bath should be mentioned, followed by a massage. This method can be recommended to persons who involve the strong tension of the vocal apparatus in thei singing lessons. This method eliminates the fatigue of voice, reduces the blood flow to them.
The simplest form of massage is stroking of the skin in the direction of the heart. Movements must be performed with light pressure. Five minutes is enough to get rid of fatigue and restore the voice power.
For hardening of the nasopharynx daily rinsing of the nasal cavity with water of +18 +20C, gradually reducing the temperature (you should feel comfortably), can be of great assistance.
Rinsing is better to be done in the morning: hold down one nostril and swallow through the other one the water from your palm. The water will come into the mouth, washing and massaging the nasal mucosa. Then do the same with the other nostril.
No need to force the intensity of water inhalations because it can cause a sharp pain. At first the water will not flow into the mouth, it is a matter of time, skill.
The result of this procedure depends on the reasonableness of the person as in any other training. Of course, salt inhalations also can be helpful, but even some simple water can be beneficial. Just do not force a result, even if the water does not come out through the mouth, as it should be in theory, it is still contributes greatly to cleaning, massage, hardening.
Very useful are gymnastic exercises that strengthen the muscles of the cardiovascular and respiratory system. Many prefer jogging to every other exercise.
All kinds of health care activities are very good for hardening and strengthening of the body. The main condition is that the person should find the right kind of training that fits to him.
It is advisable, as it's highly individual, to consult your doctor before taking up one of these exercises.