Exercising in the cold inhibits growth hormone secretion by reducing the rise in core body temperature.

Objective: Ambient temperature alters exercise induced GH secretion. It is unknown whether temperature affects GH secretion at exercise intensities above the anaerobic threshold when other factors may override the relationship seen at lower intensities.

Design: Cross-over study of ambient temperature on exercise induced GH in swimmers and rowers.

Incubation of very immature infants.

The range of thermal control and the thermoneutral range of preterm infants under 30 weeks' gestation was calculated by extrapolation of data from studies on more mature infants. Even assuming some thermoregulatory capacity, the range of control is less than 3 degrees C, the thermoneutral range is less than 0.5 degrees C, and both are greatly influenced by the rate of transepidermal water loss.

The heat balance of small babies nursed in incubators and under radiant warmers.

The heat balance of 12 healthy preterm babies (mean birth weight 1.58 kg, gestation 32 weeks, age 7 days) was studied first in an incubator and then under a radiant warmer during normal nursing. Heat production and heat loss by radiation, convection and evaporation were measured in presumed thermoneutral conditions.