CONDUCTION, CONVECTION, AND RADIATION IN A CLOSED CAVITY WITH A LOCAL RADIANT HEATER

Eight very low-birth-weight premature infants (mean birth weight 1.11 ± 0.05 [SEM] kg, mean gestation 30 ± 1 weeks, and mean age 9 ± 2 days) were studied under servocontrolled radiant warmers with and without a loosely fitted, transparent, and flexible Saran plastic blanket. Metabolic rate was significantly less in all infants when covered by the blanket (oxygen consumption was 7.99 ± 1.13 mL/kg/min v 9.00 ± 1.10 mL/kg/min uncovered, P < .001). There were also significant reductions in insensible water loss (1.86 ± 0.18 v 1.25 ± 0.20 mL/kg/h, P < .01) and in heat demand from the radiant warmer (14.3 ± 1.3 v 9.9 ± 1.4 mW/cm2, P < .001) when infants were nursed under the blanket compared with the control condition, respectively. Covering the critically ill, very low-birth-weight infant nursed under a radiant heater with a thin, transparent layer of Saran is beneficial in reducing oxygen consumption, insensible water loss, and the need for exposure to high levels of radiant heat. Further investigation to confirm the benefits and possible complications of plastic blankets should be conducted before routine use can be recommended.

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Natural Convection of Non-Newtonian Fluids in a Differentially Heated Closed Cavity

10.23919/mipro52101.2021.9597135 ◽

2021 ◽

Author(s):

Miha Rot ◽

Gregor Kosec

Keyword(s):

Natural Convection ◽

Newtonian Fluids ◽

Closed Cavity

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Test Method for Measurement of Mass Loss and Ignitability for Screening Purposes Using a Conical Radiant Heater

10.1520/e2102-21 ◽

2021 ◽

Author(s):

Keyword(s):

Mass Loss ◽

Test Method ◽

Radiant Heater

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An animal model of life-threatening hyperthermia during infancy

Journal of Applied Physiology ◽

10.1152/jappl.1992.73.1.340 ◽

1992 ◽

Vol 73 (1) ◽

pp. 340-345 ◽

Cited By ~ 12

Author(s):

D. S. Jardine ◽

R. H. Haschke

Keyword(s):

Animal Model ◽

Sudden Infant Death ◽

Sudden Infant ◽

Human Infants ◽

Normal Body Temperature ◽

Life Threatening ◽

Radiant Heater ◽

Weanling Piglets ◽

And Control ◽

Experimental Group

A mathematical model of heat balance in human infants suggests that it may be possible for severe hyperthermia to develop if an infant is unable to remove his blankets in response to overheating (thermal entrapment). This hypothesis was tested in an animal model of weanling piglets. Ten piglets were warmed in a radiant heater to rectal temperature of 41 degrees C to simulate a fever. Animals in the experimental and control groups were removed from the heater and covered with ordinary infant blankets (to a thickness of approximately 3 cm). Endogenously produced heat caused the animals to warm to 42 degrees C. At this point, the control animals were uncovered. They rapidly cooled to normal body temperature. Animals in the experimental group remained covered until they expired from hyperthermia at 43.9 +/- 0.7 degrees C (SD) after 96 +/- 43 (SD) min. These data show that lethal hyperthermia may result from thermal entrapment. This finding may help clarify the role that hyperthermia may play in illnesses such as hemorrhagic shock and encephalopathy syndrome and some cases of sudden infant death syndrome.

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