Abstract Heat-related mortality risks are a substantial component of the looming costs of climate change in the United States and globally. This article presents the results from a risk-risk survey to test whether U.S. respondents place a valuation premium on mortality risks from heat relative to cancer and transportation risks. The questionnaire exploits exogenous shocks to temperatures during a heat wave and randomized elements to further test whether preferences vary with heat exposure or the age of individuals exposed to heat risks. The results provide strong evidence that there is no valuation premium in the U.S. for heat-related risks. Subjects valued cancer risks twice as highly as heat and transportation risks, the latter of which are a common benchmark for general traumatic fatalities. While there is some evidence that subjects value heat risks more when exposed to a heat shock of approximately 3–4 °C, the size of the differential is too small to establish a statistically significant heat risk premium. Finally, subjects’ responses demonstrate no differential valuation of mortality risks to seniors versus the general population based on the preferences of the general population or the senior subsample.