HENSEL, H. 
DR. HENSEL: No, we observed only a decrease of the cold 
sensation. 
MR. ADAMS: What was the maximum impulse frequency? 
DR. HENSEL: 150 impulses/sec in the cold fibers. 
MR. ADAMS: Was this with cooling to 13° C7 
DR. HENSEL: We did not record the 150 impulses/sec in the 
hijman cold fiber I have shown. I think it was about 100 impulses/sec, 
but when cooling the most sensitive cold receptors from 34 C to 
C, the frequency will rise to about 150 impulses/sec. It depends 
on the rate of cooling. The higher the cooling rate, the hi^er the 
maximum frequency. 
MR, EAGAN: There is an inference here that one would not feel 
cold if the receptors stayed below 5 C. 
DR. HENSEL: Yes, I think so. The cold sensation will disappear 
at very low skin temperatures. 
DR. RODDIE: Do you use any painful stimuli? 
DR. HENSEL: Not yet, but this is part of our next program. 
We only used temperatures from 15 C to 43 C. 
DR. HANNON: Could this decrease pain as the temperature 
o 
goes below 20 C?I believe you say there is a decrease in sensation. 
DR. HENSEL: Yes. 
DR. HANNON: How do you determine whether this is an accom- 
modation or just a simple temperature effect? 
DR. HENSEL: Well, accommodation means that a time factor 
is involved. If the temperature is lowered to 5 C and raised again, 
the discharge will reappear and after sometime reach the initial 
level. 
64 
