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Of the 97 children in the hypothermia group and the 93 children in the control group, death or an IQ score below 70 occurred in 46 (47%) and 58 (62%), respectively (P=0.06); death occurred in 27 (28%) and 41 (44%) (P=0.04); and death or severe disability occurred in 38 (41%) and 53 (60%) (P=0.03). The CoolCap study gathered data using the ...
A thermal protective aid shall be made of a waterproof material having a thermal conductance of not more than 7,800 W/(m 2 K) and shall be so constructed that, when used to enclose a person, it shall reduce both the convective and evaporative heat loss from the wearer's body. The thermal protective aid shall:
Newborns transitioning into extrauterine life will undergo periods of reactivity. These periods are divided into three stages. The first stage occurs in the first 30 minutes of life; during this stage the infant is alert and responsive with heart rate peaking at 160-180 beats per minute and then stabilizes to a baseline rate of 100-120 beats ...
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]
This increases heat production as respiration is an exothermic reaction in muscle cells. Shivering is more effective than exercise at producing heat because the animal (includes humans) remains still. This means that less heat is lost to the environment through convection. There are two types of shivering: low-intensity and high-intensity.
Convective heat transfer, or simply, convection, is the transfer of heat from one place to another by the movement of fluids, a process that is essentially the transfer of heat via mass transfer. The bulk motion of fluid enhances heat transfer in many physical situations, such as between a solid surface and the fluid. [10]
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).
In forced convection the Reynolds number governs the fluid flow. But, in natural convection the Grashof number is the dimensionless parameter that governs the fluid flow. Using the energy equation and the buoyant force combined with dimensional analysis provides two different ways to derive the Grashof number.