Small black holes in string theory

I will describe some recent work on Euclidean Schwarzschild black holes in d+1 dimensional flat spacetime, in the limit where their Hawking temperature approaches the Hagedorn temperature. This leads to new conformal field theories, enhanced symmetry at the Hagedorn temperature, and relations to earlier work on black holes at large d. If there is time, I will also discuss an open string analog of this problem, that exhibits similar phenomena.