$\Delta T$	difference between sample surface temperature and room temperature
$\Delta T_{\mathrm{u}\mathrm{n}\mathrm{s}\mathrm{t}\mathrm{r}}$	minimum difference between sample surface temperature and room temperature after fast unstretching
$\Delta x$	sample elongation
${\kappa }_{NR}$	thermal conductivity
$\lambda$	local stretching ratio in the neck center
${\lambda }^{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l}}$	total stretching ratio
${\rho }_{NR}$	density
$\tau$	characteristic time constant for thermal relaxation
A	sample neck surface
a	sample neck length
$A_0$	initial sample neck surface
b	sample neck width
c	sample neck thickness
$C_{NR}$	specific heat capacity of natural rubber
d	fan-sample distance
F	force
h	heat transfer coefficient
$L_0$	initial grip-to-grip length
$l_c$	characteristic length measuring the neck volume-to-surface ratio
$Nu$	Nusselt number
$Pr$	Prandtl number
Q	heat
$Re$	Reynolds number
T	average surface temperature of the sample
t	time
$T_0$	room temperature
$T_i$	initial temperature
V	sample neck volume
v	stretching velocity
$V_0$	initial sample neck volume
$v_{\mathrm{a}\mathrm{i}\mathrm{r}}$	average air velocity
w	forced convection characteristic length