Gardening enthusiasts should ensure that if they grow produce in polytunnels, the structures are well ventilated, according to sector commentator Carolyn Spray.
Making her comments in the online pages of the Sunday Mail in response to a question from a horticultural devotee, she suggests that fans can also provide a way to ensure that an adequate supply of fresh air enters the tunnel and is circulated.
Continuing, Ms Spay notes that on hot days, heat can build up in a polytunnel, meaning that the roots of plants in the structures could be unable to obtain enough water from the soil, resulting in leaf tips dying and other undesirable effects.
Meanwhile, the Royal Horticultural Society suggests that polytunnels can be covered with films treated in special ways that can make them almost as efficient as glass in terms of heat retention.
It states: "Tunnels offer an economical alternative to unheated greenhouses."