“…Gleiss (1957) suggested that double glazing might solve this problem by decreasing conductive heat losses through the Perspex. From the foregoing analysis it seems that the main problem is to cut down the infant's radiant heat loss, and in these circumstances a thin inner Perspex shield, so positioned that there is a free circulation of the incubator's warm air on both sides, will be more effective than sealed doubleglazing.…”