I know the feeling. I went to a trail near the Plymouth Power Plant (the one that is across the street from a bike shop) back in 2011 when we had that 100 ddegree day. That trail has a really nice downhill section, which, at least at the time, ended in nothing. So you went down and then had to walk up. Walking up, I thought I was going to die. I had to sit against a tree and pour a bottle of cold water over me because I couldnt breath and felt like I was going to pass out. I also walked out of there with 7-8 ticks on me. I will wake up at 4am tomorrow and wont go far, probably Blue Hills. I want to get at least 13 miles in, the white and yellow triangle trails. I should be done by 7am if I'm on the trail at 4:30. I think that's doable.