Velo -- I agree riding these past few days really takes it out of you. I thought it was all the work we are doing remodelling our offices, but I think it really is the result of riding in the heat.
Last night's ride and this morning's went fine, but I feel no urge to push my commute. I just ride along at comfortable pace and drink water like its coming to an end. The heat does thin out traffic on the MUP! The weather guys promise a cooler day tomorrow and over the weekend, so maybe things will get better.