  We consider the temperature fluctuations of a small object. Classical
fluctuations of the temperature have been considered for a long time. Using the
Nyquist approach, we show that the temperature of an object fluctuates when in
a thermal contact with a reservoir. For large temperatures or large specific
heat of the object $C_v$, we recover standard results of classical
thermodynamic fluctuations $<\Delta T^2> = \frac{k_B T^2}{C_v}$. Upon
decreasing the size of the object, we argue, one necessarily reaches the
quantum regime that we call quantum temperature fluctuations. At temperatures
below $T^{*}\sim \hbar/k_{B}\tau$, where $\tau$ is the thermal relaxation time
of the system, the fluctuations change the character and become quantum. For a
nano-scale metallic particle in a good thermal contact with a reservoir,
$T^{*}$ can be on a scale of a few Kelvin.
