Wearable with temperature control

1 . A device, comprising:

a body-to-liquid heat exchanger, configured to exchange heat between a user's body and a liquid, the body-to-liquid heat exchanger comprising a conformal bladder defining a serpentine portion of a liquid-flow path, the bladder having a stress-relief aperture on an edge of the bladder and another aperture surrounded on all sides by the bladder and configured to receive a joint of the user;

a first conduit placing an inlet to the liquid-flow path in fluid communication with an outlet of a liquid-to-ambient-air heat exchanger;

a second conduit placing an outlet of the liquid-flow path in fluid communication with an inlet of the liquid-to-ambient-air heat exchanger;

the liquid-to-ambient-air heat exchanger coupled to the first conduit and the second conduit, the liquid-to-ambient-air heat exchanger comprising:

a pump in fluid communication with the liquid-flow path;

a tank comprising another serpentine portion of the liquid-flow path;

a Peltier thermoelectric cooler adjacent the tank and in thermal communication with the liquid-flow path;

a heat sink adjacent the Peltier thermoelectric cooler, with the Peltier thermoelectric cooler being disposed between the tank and the heat sink;

a fan configured to blow air onto fins of the heat sink; and

a battery configured to provide electrical power to the Peltier thermoelectric cooler, the pump, and the fan;

a valve positioned to release gas from a compressed-gas container responsive to a signal from a controller; and

a channel into which the valve is positioned to direct the gas, the channel being configured to cause the gas to flow adjacent the heat sink to remove heat from the heat sink when the gas is released by the valve.

2 . The device of claim 1 , wherein the channel is configured to recirculate the gas through multiple cooling cycles against the heat sink.

3 . The device of claim 1 , wherein the channel comprises a baffle and an actuator configured to cause the gas to stop being recirculated and ambient air to instead be circulated responsive to the gas exceeding a threshold temperature.

4 . The device of claim 1 , comprising four or more Peltier thermoelectric coolers adjacent the tank and in thermal communication with the liquid-flow path, wherein the Peltier thermoelectric coolers are also configured to apply heat to the user's body at different times from when the Peltier thermoelectric coolers are cooling the user's body.

5 . The device of claim 1 , comprising:

a garment attached to the body-to-liquid heat exchanger and configured to position the body-to-liquid heat exchanger adjacent the user's body.

6 . The device of claim 5 , wherein the garment comprises a plurality of body-to-liquid heat exchangers.

7 . The device of claim 5 , wherein the garment comprises a winch configured to bias the garment against the user's body.

8 . The device of claim 5 , wherein the garment is a vest.

9 . The device of claim 5 , wherein the garment is a knee brace.

10 . The device of claim 5 , wherein the garment is an ankle brace.

11 . The device of claim 5 , wherein the garment is a head band or hat.

12 . The device of claim 1 , comprising a controller configured to drive the Peltier thermoelectric cooler and another Peltier thermoelectric cooler on a periodic cycle with less than 100% duty cycle and out of phase with respect to one another.

13 . The device of claim 1 , comprising:

an array of needles disposed on a patch applied to an inner surface of the device, the array of needles configured to be selectively actuated by a controller to penetrate skin of the user's body.

14 . The device of claim 13 , wherein:

the array of needles is configured to effectuate transdermal delivery of an injected material.

15 . The device of claim 14 , wherein:

the material comprises a stem cell derivative.

16 . The device of claim 14 , wherein:

the material is blood plasma.

17 . The device of claim 14 , wherein:

the material is fibrin.

18 . The device of claim 13 , wherein:

the array of needles is configured to sample a fluid from a person wearing the device, the array of needles having or being coupled to a biometric sensor configured to assay the fluid.

19 . The device of claim 13 , comprising:

a hydrogel adjacent at least some needles in the array of needles.

20 . A device, comprising:

a body-contacting heat exchanger configured to provide heat to a user's body, the body-contacting heat exchanger comprising a flexible panel;

an actuator disposed on a side of the body-contacting heat exchanger away from the user's body, the actuator comprising at least one air bladder;

a conduit placing the actuator in fluid communication with a compressor;

the compressor configured to pressurize the actuator;

a heater associated with the body-contacting heat exchanger;

a controller operatively coupled to the heater and the compressor;

a valve positioned to release gas from a compressed-gas container responsive to a signal from the controller;

a channel into which the valve is positioned to direct the gas, the channel being configured to cause the gas to flow adjacent to a heat sink to remove heat from the heat sink when the gas is released by the valve; and

a battery configured to provide electrical power to the heater, the compressor, and the controller,

wherein, when the actuator is pressurized, the actuator presses the body-contacting heat exchanger against the user's body while the controller operates the heater to maintain a target temperature at the body-contacting heat exchanger.

21 . The device of claim 20 , further comprising:

a thermally reflective layer on a side of the body-contacting heat exchanger away from the user's body; and

a layer adjacent the user's skin.

22 . The device of claim 20 , wherein the heater is a body-to-liquid heat exchanger configured to receive heated liquid from an ambient-to-liquid heat exchanger and transfer heat from the liquid to the user's body.

23 . The device of claim 22 , wherein the body-to-liquid heat exchanger comprises thermoelectric devices, a heat sink, and a fan, and the controller drives the thermoelectric devices with less than 100% duty cycle and out of phase.

24 . The device of claim 20 , wherein:

the device is configured to be worn across a joint region, the body-contacting heat exchanger being positionable adjacent the joint and the actuator being disposed on a side of the body-contacting heat exchanger opposite a skin-contacting surface and arranged about an axis of rotation of the joint; and

when pressurized, the actuator presses the body-contacting heat exchanger against the user's body while permitting relative rotation about the axis of rotation.

25 . The device of claim 24 , wherein the joint region comprises an ankle.

26 . The device of claim 20 , wherein the device is wearable as a brace and further comprises straps or a winch configured to bias the brace against the user's body.

27 . The device of claim 20 , further comprising a temperature sensor on the body-contacting heat exchanger.