Time Lord - Physical Characteristics

Physical Characteristics

Time Lords look human (or, as the Eleventh Doctor tells Amy Pond in the The Beast Below, humans "look Time Lord", as Time Lords came first), but differ from them in many respects. Physiological differences from humans include two hearts which normally beat at 170 beats per minute, an internal body temperature of 15 degrees Celsius (59 degrees Fahrenheit) and a "respiratory bypass system" that allows them to survive strangulation. Time Lords can also survive full exposure to the vacuum of space with no ill effects, though when in a vacuum for an extended period a Time Lord must take a supply of air along, or suffocate. Time Lords also seem to have an increased resilience to higher frequencies of sound, as seen in "The Christmas Invasion" (although this may simply be the excess energy from his recent regeneration, or their hearing range may not go as high as a human's). and "Partners in Crime". If severely injured, Time Lords can go into a healing coma which lowers their body temperature to below freezing. In the serial Destiny of the Daleks, Romana was able to voluntarily stop both of her hearts beating, to fool the Daleks into believing that she was dead. The Doctor also shows a greater tolerance to cold compared to humans in Planet of the Ood and even Romana in The Ribos Operation, and in "42" the Doctor states he is able to survive at absolute zero for a short period of time; this makes sense, given their relative lower average body temperature. In "World War Three", the Doctor is able to shake off an electrocution attempt which is fatal to a number of humans, and appears unaffected by the energy whip wielded by the Sycorax in "The Christmas Invasion". In "Smith and Jones" the Tenth Doctor says that the radiation given off by X-rays pose no real threat to Time Lords, and proceeds to absorb an amount that would be lethal to a human, which he subsequently expels through his foot. Time Lords, or at least the Doctor, can read extremely quickly. The End of Time shows the Doctor as being capable of surviving (for a short period) a massive burst of radiation that would have killed anything else instantly. However, the radiation burst caused enough damage to start a regeneration cycle.

Time Lords are extremely long-lived, routinely counting their ages in terms of centuries; the Doctor claimed in The War Games that Time Lords could live "practically forever, barring accidents." The series has suggested that Time Lords have a different concept of ageing than humans. In Pyramids of Mars, the Doctor considers an age of 750 years to be "middle-aged". In "The Stolen Earth", he refers to being a "kid" at 90 years old.

In The Daleks' Master Plan the First Doctor is able to resist the effects of the Time Destructor better than his companions, who are visibly aged by it; one of them, Sara Kingdom ages to dust before the Destructor device can be reversed. The Fourth Doctor is briefly aged 500 years in The Leisure Hive, leaving him an old man but still active. A similar situation occurred in "The Sound of Drums", where the Master uses specially made technology to age the Tenth Doctor by a century, leaving him in a frail and helpless state. A further application of this technology in the following episode, "Last of the Time Lords", suspends the Doctor's capacity to regenerate, showing the effects of 900 years of life without regeneration.

In The Two Doctors, the Doctor states that the "Rassilon Imprimatur" allows Time Lords to safely travel through time, becoming symbionts with their TARDISes, and that the reason other species are incapable of developing time travel are that they lack the imprimatur. However, he implies later that he was lying about at least some of this information to mislead the Sontarans. At the beginning of The Trial of a Time Lord, the Doctor suggests that a number of elder Time Lords were able to use their combined mental energy to summon his TARDIS against his will.

In The Unicorn and the Wasp, the Tenth Doctor is able to overcome the effects of cyanide by "stimulating the inhibited enzymes into reversal", a process he referred to as going through "detox".

In the episode Cold Blood, the Eleventh Doctor experiences excruciating pain when the Silurian attempts to decontaminate him of surface bacteria. The Doctor states this would kill him, most likely due to the scanners being programmed to 'detox' humans and therefore being unaware of what elements the Doctor requires.