What is TPA (thermal protective aids)

Writer: Aaron Wu

January 19 ,2018

DX Marine production department-clothing

 A Thermal Protective Aid (TPA) is a body-warming garment made of waterproof material, although it is not an in-water garment The TPA must envelope the whole body (except the face) and may be provided with or w arms and / or legs: TPA's without arms or legs have the appearance of a “sack” which encases the whole person.

The material must meet a certain standard of thermal conductance so that the wearer experiences a reduction of both conductive and evaporative heat loss.

The TPA must be large enough for a person wearing a lifejacket, capable of being easily donned without assistance in a survival craft or rescue boat, and, if it impairs the ability to swim, the wearer must be able to remove the TPA in the water in not more than two minutes.


Persons suffering from the effects of cold (hypothermia) may be placed inside a TPA to assist recovery, or a person may be provided with a TPA to prevent them becoming hypothermic. If the TPA is large enough someone suffering from the effects of cold may be placed inside together with another warmer person whose body heat will render assistance to the colder person.

When wearing a TPA if there is the possibility of entering the water (e.g. through life raft capsize) a lifejacket should also be worn. TPA's are not in-water garments and have no water seals at the face or in the zip or closures, so when in the water they will become swamped and present a significant danger.

Because TPA's are usually supplied individually in sealed bags one or two spares should be carried for demonstration and practice purposes.



Minimum number of TPA's required

Open Lifeboat

100% of the lifeboat capacity.

This may be reduced by the number of immersion suits provided for the operating crew.

Partially enclosed Lifeboat Enclosed Lifeboat Life raft (with canopy) Rescue Boat Fast Rescue Boat

10% of the lifeboat / liferaft / rescue boat capacity or two, whichever is the greater.

Open—Reversible Liferaft (non-SOLAS)

Not required (except Sweden)

Ro-Ro Emergency Equipment Locker (UK Flagged passenger ro-ro vessels only)

A total of six TPA's and/or blankets


Thermal Protective Aids are normally individually packed and often vacuum packed. They are very low cost items and repair is not generally economically viable. The units should be visually inspected on a regular basis and if the package is found to be damaged the TP A should be replaced.