NiMh peaks 120-125F. Prob with using temp to shutoff charger to protect batts from overheating is most temps sensors lag behind the actual temp - at least with the Ice and TC1030 type temp sensor. Those have to be set for a low temp to have any utility. I quit using mine, just not dependable.

This may be a better sensor and track temps better. They show 50C in the manual and thats 122F and pretty close to where these should peak. I'd set it at 125F and monitor the 1st charge. This should reduce the number of shutdowns you're seeing now and may charge all the way thru. The heat the batts generate depends on the peak sensitivity setting, charge rate and to some degree, the age of the batts. You might need to use 130F or reduce the peak setting and or the charge rate.

At no point let them get so hot than you can't hold them. They are supposed to be hot, but not so hot you can't hold them.