A hot-button type heat alert safety device attachable to a surface, such as metal or glass, for warning individuals that the surface is hot, comprising a thermochromic composition, a button-shaped container for housing the composition, having a convex face, the convex face overlying said composition and the container being transparent in at least a portion of the container overlying the thermochromic composition. The thermochromic composition is designed to undergo and maintain a readily perceptible color change whenever the temperature of the hot surface exceeds a predetermined temperature and reveal a heat warning symbol underneath the thermochromic composition which communicates that the surface is dangerously hot, the heat warning symbol being substantially visible through the convex face of the container.