A<unk>  is an air-conditioned public space set up by local authorities to temporarily deal with the health effects of a heat wave.<unk> s are meant to prevent hyperthermia caused by heat, humidity, and poor air quality.<unk> s provide shade, water, and restrooms; medical attention and referrals to social services may also be offered. Their services are aimed at the homeless, at-risk populations such as the elderly, and those without air conditioning. As the danger of heat waves has risen in the public consciousness,<unk> s are increasingly used in larger cities such as New York City, Chicago, Boston, and Toronto, as well as less urban population areas.<unk> s may also be used in places like Portland and Seattle where home air conditioning is rare but summer can bring temperatures exceeding for several days. Similarly, during the 2018 European heat wave and fires that reached northern Scandinavia, a supermarket in Finland was temporarily used as a<unk> . They are usually sited at multiple locations throughout a municipality, such as public libraries, community<unk> s, senior<unk> s, and police stations. Another health measure sometimes taken during heat waves is to extend operational hours at public beaches and swimming pools.
Cooling center
Ussing chamber
Brain–brain interface
Apothecaries' system
Neuroeffector junction
Growth cone
Optic cup 
Immune cycle