Linear regression line between temperature of the index finger (T
index) and thermal sensation of the hands (a: left follicular phase, right luteal phase, n = 6), and temperature of the hallux (T
hallux) and thermal sensation of the toes (b: left: follicular phase, right luteal phase, n = 7) at 0–120 min. The gray lines represent the linear regressions for each subject. The bold black lines and equations were based on the average slope and intercept of the regression lines, which were estimated from results for six (a) or seven (b) subjects. Correlation coefficients (R) and probability values (P) represent the maximum and minimum values for the subjects