The temperature rise induced by illumination in a (YAl3(BO3),) crystal activated with Nd3+ luminescent ions has been measured under spontaneous and stimulated emission conditions. Due to the low-quantum efficiency (18-26%) of the Nd3+ ion in this crystal, a remarkable temperature decrease (13 degrees at 150 mW of absorbed pump power) is observed when switching from spontaneous to stimulated emission. This 'thermal cooling' can also be used to estimate the B Einstein coefficient. The value we have obtained, B = 2.3 x 10(14) m(3) J(-1) s(-1) for the main laser transition, is in good agreement with those reported by other methods.