This plot was arrived at by averaging all pressure readings over 10 F interval temperature ranges from 0 to 100 F, plotting the temperature at the mid point of the range. For example, the average of all pressure readings made at ambient temperatures between 31 and 40 F was plotted at 35 F. Even with the scatter, a trend toward lower systolic pressure with rising ambient temperatures can be detected. F. A plot of the pulse rate vs. the ambient temperature is presented at the left. The pulse rate tends to rise at temperatures above 60 F. To further investigate the suspected correlation a linear correlation matrix for the temperature, pulse, systolic and diastolic pressure for data at 67 years old was calculated using a statistics package. A correlation of zero is no relationship at all between the variables and at 1.0 it is perfect.
Values here indicate some intermediate degree of relatationship for the linear model.
The strongest correlation is between the temperature and systolic pressure. The corrrelation of temperature with diastolic pressure and pulse is even less. Generally, correlations of less than 0.9 are viewed with some suspect. The low degree of correlation observed may be due to nonlinear relationships between the variables. This is probably the case.