Changes

''[[Swedana]]'' should only be administered following a proper ''[[snehana]]'' (unless indicated otherwise). On application of unctuous substances like oil (''taila'') on various body parts, ''sweda'' forms an intervening viscous layer between the skin and the immediate environment prior to transdermal drug absorption. Thus the heat lost through sudation, along with large amounts of fluid and a marginal amount of Na+ and Cl- ions through radiation / conduction / convection / evaporation (which could potentially impair thermoregulation or cause hypothermia) does not happen too rapidly. Also, the procedure of ''[[swedana]]'' promotes the transdermal absorption of the ''sneha'' by inducing peripheral vasodilatation. However, environmental humidity and the duration of ''[[swedana]]'' procedure has to be strictly monitored, as exposure to small rise in temperature for a prolonged time can have a greater impact (more evaporation) than exposure to high temperature for a short time in a humid atmosphere<ref name="ref1">Cabanae, M., (2006), Journal of Applied Physiology, 100, Adjustable set point, 1338 – 1346.</ref>. Hence ''yathavath prayojithaihi'' has been written expressly to denote the optimal exposure to ''swedana''.

''[[Swedana]]'' should only be administered following a proper ''[[snehana]]'' (unless indicated otherwise). On application of unctuous substances like oil (''taila'') on various body parts, ''sweda'' forms an intervening viscous layer between the skin and the immediate environment prior to transdermal drug absorption. Thus the heat lost through sudation, along with large amounts of fluid and a marginal amount of Na+ and Cl- ions through radiation / conduction / convection / evaporation (which could potentially impair thermoregulation or cause hypothermia) does not happen too rapidly. Also, the procedure of ''[[swedana]]'' promotes the transdermal absorption of the ''sneha'' by inducing peripheral vasodilatation. However, environmental humidity and the duration of ''[[swedana]]'' procedure has to be strictly monitored, as exposure to small rise in temperature for a prolonged time can have a greater impact (more evaporation) than exposure to high temperature for a short time in a humid atmosphere<ref name="ref1">Cabanae, M., (2006), Journal of Applied Physiology, 100, Adjustable set point, 1338 – 1346.</ref>. Hence ''yathavath prayojithaihi'' has been written expressly to denote the optimal exposure to ''swedana''.

Proper application of ''[[snehana]]'' (''abhyanthara'' and ''bahya'') and ''[[swedana]]'' enhances gastro-intestinal motility. A study enumerates the instantaneous as well as prolonged benefits of continued ''[[swedana]]'', concluding that habitual use of ''[[swedana]]'' improves one’s heat tolerance capacity and physical endurance, while observing increased autonomic functions among patients due to intermittent purposeful heat stress.<ref>Sanjeev Rastogy & Francesco Chiappelli, (2013 April – June), AYU, 34(2): Heamodynamic effects of Sarvanga swedana (Ayurvedic passive heat therapy): a pilot observational study 154-159.</ref> There are numerous studies which claim that gastrointestinal motility disorders are caused due to decreased autonomic activity and its therapeutic increase, therefore helps cure motility disorders, thereby improving bowel-bladder functioning. [verse 3-5]

Proper application of ''[[snehana]]'' (''abhyanthara'' and ''bahya'') and ''[[swedana]]'' enhances gastro-intestinal motility. A study enumerates the instantaneous as well as prolonged benefits of continued ''[[swedana]]'', concluding that habitual use of ''[[swedana]]'' improves one’s heat tolerance capacity and physical endurance, while observing increased autonomic functions among patients due to intermittent purposeful heat stress.<ref name="ref5">Sanjeev Rastogy & Francesco Chiappelli, (2013 April – June), AYU, 34(2): Heamodynamic effects of Sarvanga swedana (Ayurvedic passive heat therapy): a pilot observational study 154-159.</ref> There are numerous studies which claim that gastrointestinal motility disorders are caused due to decreased autonomic activity and its therapeutic increase, therefore helps cure motility disorders, thereby improving bowel-bladder functioning. [verse 3-5]

Environmental and age related factors also need to be considered for sudation. In extremely warm regions or during the peak of summer, there is remarkable body dehydration. And in an intensely humid climate or in an ill ventilated room where there is peripheral heat production from the body surface (and yet minimal evaporation), sudation has to be strictly monitored and precautionary procedures have to be well thought-out. Cold seasons are ideal for ''[[swedana]]'' procedures because body homeostasis favors or demands heat (evident from the behavioral response mechanisms adopted by each one of us in cold seasons). Among specific fomentation techniques, ''sarvangasweda'' is contraindicated in individuals at the extremes of age (i.e., infants and very elderly people) where there is ineffective thermoregulation, although ''ekanga'' and ''mridu sweda'' could be prescribed. [verse 6]

Environmental and age related factors also need to be considered for sudation. In extremely warm regions or during the peak of summer, there is remarkable body dehydration. And in an intensely humid climate or in an ill ventilated room where there is peripheral heat production from the body surface (and yet minimal evaporation), sudation has to be strictly monitored and precautionary procedures have to be well thought-out. Cold seasons are ideal for ''[[swedana]]'' procedures because body homeostasis favors or demands heat (evident from the behavioral response mechanisms adopted by each one of us in cold seasons). Among specific fomentation techniques, ''sarvangasweda'' is contraindicated in individuals at the extremes of age (i.e., infants and very elderly people) where there is ineffective thermoregulation, although ''ekanga'' and ''mridu sweda'' could be prescribed. [verse 6]

A sudden increase in body temperature produces a corresponding increase in cutaneous vascular conductance. This is followed by an increase in systemic conductance which produces alterations in cardiac output (decrease in central venous pressure and increase in cardiac output thereby increased left ventricular ejection fraction), oxygen consumption and water loss. Heart rate increases.  

A sudden increase in body temperature produces a corresponding increase in cutaneous vascular conductance. This is followed by an increase in systemic conductance which produces alterations in cardiac output (decrease in central venous pressure and increase in cardiac output thereby increased left ventricular ejection fraction), oxygen consumption and water loss. Heart rate increases.  

There is a significant hemodynamic change at the beginning of ''[[swedana]]'' like significant cardiovascular stress which causes an increase in blood pressure (systolic and diastolic) and pulse rate. Whole body fomentation is therefore contraindicated in elderly and those with cardiomyopathy, congestive heart disease, bundle branch block, anemia, MI, hyperthyroidism etc.<ref> Sanjeev Rastogy & Francesco Chiappelli, (2013 April – June), AYU,34(2): Hemodynamic effects of Sarvanga swedana ( Ayurvedic passive heat therapy): a pilot observational study 154-159.</ref> Extra caution needs to be exercised when it comes to administering ''[[swedana]]'' procedure to patients with heart conditions .

There is a significant hemodynamic change at the beginning of ''[[swedana]]'' like significant cardiovascular stress which causes an increase in blood pressure (systolic and diastolic) and pulse rate. Whole body fomentation is therefore contraindicated in elderly and those with cardiomyopathy, congestive heart disease, bundle branch block, anemia, MI, hyperthyroidism etc.<ref name="ref5"/> Extra caution needs to be exercised when it comes to administering ''[[swedana]]'' procedure to patients with heart conditions .

Regarding eyes, the scientific community is interested in knowing more about the side effects of transpupillary thermotherapy (TTT). A study conducted on normal mouse retina reveals that retinas  treated with a power of 70 mW exhibited progressive retinal damage that was almost exclusively restricted to the photo-receptors. In those cases, early damage to the outer segments of the photo-receptors was seen one day after the thermotherapy and saw degeneration of outer nuclear layer after five days. At the same time, an accumulation of pigmented cells, presumably of macrophages, was seen in the sub-retinal space. No apparent damage was seen in the RPE or choroid. Today, researchers are considering the importance of using sub-threshold effects while applying TTT to patients with neurovascular age-related macular degeneration.<ref>A.P. Kvanta, P. Algvere  Department of Ophthalmology, St Erik's Eye Hospital, Stockholm, Sweden, Effect of Transpupillary Thermotherapy (TTT).</ref> [verse 10] These practices are very common nowadays except for the usage of wheat balls.  When lotus petals are unavailable, rose flower petals are substituted these days. Even cotton balls soaked in cold water, bandaged with cloth are commonly used to protect eyes while sudation. [verse 11]

Regarding eyes, the scientific community is interested in knowing more about the side effects of transpupillary thermotherapy (TTT). A study conducted on normal mouse retina reveals that retinas  treated with a power of 70 mW exhibited progressive retinal damage that was almost exclusively restricted to the photo-receptors. In those cases, early damage to the outer segments of the photo-receptors was seen one day after the thermotherapy and saw degeneration of outer nuclear layer after five days. At the same time, an accumulation of pigmented cells, presumably of macrophages, was seen in the sub-retinal space. No apparent damage was seen in the RPE or choroid. Today, researchers are considering the importance of using sub-threshold effects while applying TTT to patients with neurovascular age-related macular degeneration.<ref>A.P. Kvanta, P. Algvere  Department of Ophthalmology, St Erik's Eye Hospital, Stockholm, Sweden, Effect of Transpupillary Thermotherapy (TTT).</ref> [verse 10] These practices are very common nowadays except for the usage of wheat balls.  When lotus petals are unavailable, rose flower petals are substituted these days. Even cotton balls soaked in cold water, bandaged with cloth are commonly used to protect eyes while sudation. [verse 11]