An access device for placing a medical article within a body space includes a needle, a dilator, and a sheath. The needle can include an elongated needle body and a hub from which the needle body extends. The dilator can be slideably disposed on the needle body and include a dilator hub and an elongated dilator shaft that extends from the dilator hub. The sheath can include a tubular sheath body disposed on the dilator and a sheath hub coupled with the tubular sheath body. The tubular sheath body can include a material that exhibits a reduced rigidity upon exposure to heat.
