Night of the Big Heat- Peter Cushing, Christopher Lee, Jane Merrow-1967 IMDb 5.6/10

While mainland Britain shivers in deepest winter, the northern island of Fara bakes in the nineties. The boys at the Met station have no more idea what is going on than the regulars at the Swan. Only a stand-offish visiting scientist suspects aliens are to blame. Meanwhile the new secretary to the local best-selling author is raising the temperature in her own way.