Congratulations on your first healthy lunch-time activity. I wish I worked someone nice where I could go for a walk at lunch. I try to spend as little time "hanging around" Wythenshawe as possible. I don't think there are any scenic walks unless you find barbed wire and job centres scenic...
But yes! Our cool water machine also keeps selling me the idea of cool water as a metabolism boost. I think it may be true for my diet has faltered greatly since my birthday (tonight Paul and I are going for a Chinese meal) but I haven't put anymore weight back on (yet I hasten to add). I am settled around the "just under 10st" mark which I find an acceptable weight. I just need to get fit (but won't cos I'm lazy). You put me to shame! To shame!