OK, your final challenge about dissociation is temperature. Here's a hint: for every ATP that's broken down, heat is released. So, think about where you'd expect the highest levels of heat -- at the working cells or the lungs? And do you want dissociation to be high or low at this location? Will an increase or decrease in temperature be associated with an increase in Hb-O2 dissociation? a. increase in temperature b. decrease in temperature