Search results
Results from the WOW.Com Content Network
Physiology: Newborns lack the ability of thermogenesis due to underdeveloped shivering mechanism. Body heat is lost through conduction, convection, and radiant heat. [ 1 ] Thermoregulation is achieved through several methods: the metabolism of brown fat and Kangaroo care, also known as skin to skin.
Human heat-loss mechanisms are limited primarily to sweating (which dissipates heat by evaporation, assuming sufficiently low humidity) and vasodilation of skin vessels (which dissipates heat by convection proportional to the temperature difference between the body and its surroundings, according to Newton's law of cooling).
Convection-cooling is sometimes loosely assumed to be described by Newton's law of cooling. [6] Newton's law states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings while under the effects of a breeze. The constant of proportionality is the heat transfer coefficient. [7]
In shivering, the heat is the main intended product and is utilized for warmth. [citation needed] Newborn babies, infants, and young children experience a greater (net) heat loss than adults because of greater surface-area-to-volume ratio. As they cannot shiver to maintain body heat, [citation needed] they rely on non-shivering thermogenesis.
The heat transfer coefficient h depends upon physical properties of the fluid and the physical situation in which convection occurs. Therefore, a single usable heat transfer coefficient (one that does not vary significantly across the temperature-difference ranges covered during cooling and heating) must be derived or found experimentally for ...
There are four avenues of heat loss: convection, conduction, radiation, and evaporation. If skin temperature is greater than that of the surroundings, the body can lose heat by radiation and conduction. But, if the temperature of the surroundings is greater than that of the skin, the body actually gains heat by radiation and conduction. In such ...
Heat syncope, also referred to as exercise-associated collapse, is a moderate form of heat-related illness characterized by a temporary loss of consciousness. Unlike heat exhaustion, heat cramps and heat syncope do not have systemic effects. Heat exhaustion is a precursor to heat stroke, a severe form of heat-related illness.
Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term, and more for those that are born prematurely. [1] WHO estimates that 4 million neonatal deaths occur yearly due to birth asphyxia, representing 38% of deaths of children under 5 years of age. [2]