The strength of metals increases with increasing temperature at extreme strain rates, a phenomenon that is counterintuitive as most materials soften under such conditions. Using microballistic impact testing at strain rates greater than 10^4 s^-1, researchers found that the strength of copper increased by about 30% for a 157 °C increase in temperature, effects also observed in pure titanium and gold. This behavior is attributed to a transition from thermally activated strengthening to ballistic transport of dislocations, where drag through phonon interactions enhances strength. The study provides insights into the deformation mechanisms at high strain rates and suggests new strategies for materials design under extreme conditions. The results highlight the importance of considering these mechanisms when predicting material properties in high-speed manufacturing and hypersonic transport applications.The strength of metals increases with increasing temperature at extreme strain rates, a phenomenon that is counterintuitive as most materials soften under such conditions. Using microballistic impact testing at strain rates greater than 10^4 s^-1, researchers found that the strength of copper increased by about 30% for a 157 °C increase in temperature, effects also observed in pure titanium and gold. This behavior is attributed to a transition from thermally activated strengthening to ballistic transport of dislocations, where drag through phonon interactions enhances strength. The study provides insights into the deformation mechanisms at high strain rates and suggests new strategies for materials design under extreme conditions. The results highlight the importance of considering these mechanisms when predicting material properties in high-speed manufacturing and hypersonic transport applications.