We report on the photochemical recording of long-period fiber gratings (LPFGs) in a photonic crystal fiber made of pure fused silica. Such inscription is based on two-photon absorption (TPA) of high-intensity $(\sim 300\mathrm{GW}∕{\mathrm{cm}}^2)$ $264\mathrm{nm}$ $220\mathrm{fs}$ pulses and brings about LPFGs of high strength and narrow peak width. The characteristic fluence value for the inscription is 1 order of magnitude less than that for a standard telecom fiber irradiated under similar conditions. The temperature sensitivity of TPA-induced LPFGs is $\sim 300\mathrm{pm}∕°\mathrm{C}$ and overcomes that of LPFGs inscribed by other nonphotochemical methods by 2 orders of magnitude.