Large numbers of people really do, even today, die of both cold and heat. That's one of the dangers for for people who are homeless or too poor to pay to heat their homes properly. If temperatures change, the change in death rates should be measured using the overall change in death rates, not just the change in heat deaths. If that statement about measuring the overall impact of climate change on death rates using net change in death rates constitutes "climate change denial" for you, then a "form of climate change denial" is a form of religious heresy for you, and there's no point arguing mere statistical matters.