Novel nonionic cellulose ethers exhibit a reduced degree of thermal thinning and are efficient thickeners at elevated temperatures. The nonionic cellulose ether has hydroxyethyl groups and is further substituted with one or more hydrophobic substituents. The cellulose ether further has at least one of the properties a), b) or c): a) a retained dynamic viscosity, % η80/25, of at least 30 percent, wherein % η80/25=[dynamic solution viscosity at 80° C./dynamic solution viscosity at 25° C.] 100, the dynamic solution viscosity at 25° C. and 80° C. being measured as 1% aqueous solution; b) a storage modulus of at least 15 Pascals at 25° C. and a retained storage modulus, % G′80/25, of at least 12 percent, wherein % G′80/25=[storage modulus at 80° C./storage modulus at 25° C.] 100, the storage modulus at 25° C. and 80° C. being measured as a 1% aqueous solution; c) a critical association concentration of less than 15 ppm as measured by light-scattering.