Most concrete footpaths are cast without steel reinforcement and in segments between bituminous joints, with the joints intended to accommodate thermal expansions (and contractions) of the pavement. However, a combination of prolonged heatwave conditions and the ingress over time of material into the joints produces a situation in which the pavement does not deflect in its plane, but instead experiences a sudden upheaval buckle between the joints. These buckles are quite abundant, are increasing in number with hotter days, and they pose a risk to pedestrian safety, necessitating costly repair by regulatory bodies. Based on an energy formulation, this paper develops a solution in closed form with which to assess the vulnerability of a footpath to blow up (or to experience an upheaval buckle) on hot days as a function of the ambient temperature, material properties, and geometric layout. The solution allows for the design of a pavement that has a low probability of upheaval during its intended life, and for assessing the likelihood of existing pavements for such buckling.