The 35C value is suggested as an upper limit. Lower WBTs have already been shown to be deadly amongst the more vulnerable. I agree about tree planting being a

The 35C value is suggested as an upper limit. Lower WBTs have already been shown to be deadly amongst the more vulnerable. I agree about tree planting being a sensible precaution to take - preventing sun from reflecting off tarmac and concrete is going to help at least a bit as well as the other benefits.